Dear Sir,
I unable to insert value Year, Month, INDICATER_TYPE.
    <form id="form1" runat="server">
        <table border="1" cellpadding="0" cellspacing="0" align="left" weight="400" class="auto-style6">
            <tr>
                <td height="30" valign="top" colspan="2" bgcolor="navy" class="auto-style3">
                    <br>
                    <font color="#FF9900" size="+2" face="Tahoma"><b>Safety Lead /Lag</b></font></td>
                <br />
            </tr>
            <table border="1" cellpadding="0" cellspacing="0" align="left" weight="400" class="auto-style6">
                <tr>
                    <br />
                    <td class="auto-style18">
                        <b>Emp ID </span>:</b><br />
                        <asp:TextBox ID="txtEMPNO" runat="server" Width="140" Height="25px" />
                    </td>
                    <td class="auto-style18">
                        <b>Name</span>:</b><br />
                        <asp:TextBox ID="txtNAME" runat="server" Width="140" Height="25px" />
                    </td>
                    <td class="auto-style18">
                        <b>Department</span> :</b><br />
                        <asp:TextBox ID="txtDEPARTMENT" runat="server" Width="140" Height="25px" />
                    </td>
                    <td><strong>Select Year:</b></strong><br />
                        <asp:DropDownList ID="ddl_Year" runat="server" Width="140" Height="25px">
                        </asp:DropDownList></strong>
                 </td>
                    <td><b>Select Month:</b><strong><br />
                        <asp:DropDownList ID="ddl_Month" runat="server" Width="140" Height="25px">
                        </asp:DropDownList></strong></a></td>
                    <td class="auto-style4"><a align="left" href="login.aspx"><strong><font colore="red">Logout</font></strong></a></td>
                </tr>
                <tr>
                    <td class="auto-style18">
                        <strong>Description</strong><b>:</b><br />
                        <asp:DropDownList ID="DropDownList2" runat="server" CssClass="auto-style2" Height="27px" Width="169px" onChange="changecat(this.value);">
                            <asp:ListItem>--Select--</asp:ListItem>
                            <asp:ListItem>Visits</asp:ListItem>
                            <asp:ListItem>Training</asp:ListItem>
                            <asp:ListItem>PepTalk</asp:ListItem>
                            <asp:ListItem>Analaysis</asp:ListItem>
                        </asp:DropDownList>
                        <br />
                        <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="DropDownList1"
                            ErrorMessage="Required!" ForeColor="Red" InitialValue="--Select--"></asp:RequiredFieldValidator>
                    </td>
                    <td class="auto-style11">
                        <strong>Type</strong><b>:</span><br />
                        </b>
                        <asp:DropDownList ID="DropDownList3" runat="server" CssClass="auto-style2" Height="27px" Width="169px">
                            <asp:ListItem>--Select--</asp:ListItem>
                        </asp:DropDownList>
                        <br />
                        <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="DropDownList1"
                            ErrorMessage="Required!" ForeColor="Red" InitialValue="--Select--"></asp:RequiredFieldValidator>
                    </td>
                    <td class="auto-style12">
                        <b>Complied:</span><br />
                        </b>
                        <asp:DropDownList ID="DropDownList1" runat="server" CssClass="auto-style2" Height="27px" Width="169px">
                            <asp:ListItem>--Select--</asp:ListItem>
                            <asp:ListItem>Yes</asp:ListItem>
                            <asp:ListItem>No</asp:ListItem>
                        </asp:DropDownList>
                        <br />
                        <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ControlToValidate="DropDownList1"
                            ErrorMessage="Required!" ForeColor="Red" InitialValue="--Select--"></asp:RequiredFieldValidator>
                    </td>
                    <td class="auto-style5">
                        <b>Date:<br />
                            <asp:TextBox ID="txtDATE" runat="server" placeholder="mm/dd/yyyy" Height="25px" Width="160px"></asp:TextBox>
                            <br />                       
                    <td class="auto-style5">
                        <strong>Remark:</strong>
                        <asp:TextBox ID="txtREMARK" runat="server" Height="25px" Width="180px" />
                        <asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server" ErrorMessage="Remark can't be blank." ControlToValidate="txtREMARK" ForeColor="Red"></asp:RequiredFieldValidator>
                    </td>
                    <td class="auto-style4">
                        <asp:Button ID="btnAdd" runat="server" Text="Add" OnClick="Insert" CssClass="auto-style1" Height="25px" Width="100px" />
                    </td>
                </tr>
                <table border="1" cellpadding="0" cellspacing="0" align="left" weight="400" class="auto-style6">
                    <tr>
                        <td class="auto-style6">
                            <script type="text/javascript">
                                var TargetBaseControl = null;
                                window.onload = function () {
                                    try {
                                        //get target base control.
                                        TargetBaseControl =
                                            document.getElementById('<%= this.GridView1.ClientID %>');
                                    }
                                    catch (err) {
                                        TargetBaseControl = null;
                                    }
                                }
                                function TestCheckBox() {
                                    if (TargetBaseControl == null) return false;
                                    //get target child control.
                                    var TargetChildControl = "chkSelect";
                                    //get all the control of the type INPUT in the base control.
                                    var Inputs = TargetBaseControl.getElementsByTagName("input");
                                    for (var n = 0; n < Inputs.length; ++n)
                                        if (Inputs[n].type == 'checkbox' &&
                                            Inputs[n].id.indexOf(TargetChildControl, 0) >= 0 &&
                                            Inputs[n].checked)
                                            return true;
                                    alert('Select at least one checkbox!');
                                    return false;
                                }
                            </script>
                            <script src="//code.jquery.com/jquery-2.1.1.min.js"></script>
                            <script type='text/javascript'>
                                $(function () {
                                    // When a Button is clicked on your page, disable everything and display your loading element
                                    $(':button,:btnSendMail_Click').click(function () {
                                        // Disable everything
                                        $('*').prop('disabled', true);
                                        // Display your loading image (centered on your screen)
                                        $('').append("<img style='top: 45%; position: absolute; height: 100px; width: 100px;background: black;left: 45%;' src='<img src="30.gif" />' />");
                                    });
                                });
                            </script>
                            <td class="auto-style6"> <td class="auto-style6"> <td class="auto-style6">
                            <asp:Button ID="btnSendMail0" runat="server" CausesValidation="true" CssClass="auto-style8" Height="31px" OnClick="btnSendMail_Click" OnClientClick="javascript:return TestCheckBox();" Text="Submit " Width="75px" />
                        <td class="auto-style6"> <td class="auto-style6"> <td class="auto-style6"> 
                </table>
    </form>
<script src="js/jquery-3.4.1.min.js"></script>
<script src="jquery-ui-1.12.1.custom/jquery-ui.min.js"></script>
<script>
    $(document).ready(function () {
        $("#txtDATE").datepicker({ minDate: "-1M -28D", maxDate: "+0M +0D", changeMonth: true, changeYear: true });
    });
  </script>
<script>
    var mealsByCategory = {
        Training: ["Lead"],
        Visits: ["Lead"],
        Analaysis: ["Lag"],
        PepTalk: ["Lead"]
    }
    function changecat(value) {
        if (value.length == 0) document.getElementById("DropDownList3").innerHTML = "<option></option>";
        else {
            var catOptions = "";
            for (categoryId in mealsByCategory[value]) {
                catOptions += "<option>" + mealsByCategory[value][categoryId] + "</option>";
            }
            document.getElementById("DropDownList3").innerHTML = catOptions;
        }
    }
</script>
 
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                this.BindGrid();
            }     
            int currentYear = DateTime.Today.Year;
            ddl_Year.Items.Clear();
            ddl_Year.Items.Add("Select");
            for (int i = 2; i >= 0; i--)
            {
                int fy = currentYear - i;
                int fy1 = fy + 1;
                if (DateTime.Now.Date > Convert.ToDateTime(fy + "-03-31").Date)
                {
                    ddl_Year.Items.Add(fy.ToString() + "-" + fy1.ToString());
                }
            }
            txtDATE.Text = DateTime.Now.ToString();
          
            if (Session["EmpName"] == null)
                Response.Redirect("login.aspx");
            else
            {
                String EmplooyeId = Convert.ToString((int)Session["empid"]);
                String empid = Session["empid"].ToString();
                String EmpName = Session["EmpName"].ToString();
                String Department = Session["Department"].ToString();
                txtEMPNO.Text = "" + empid + "";
                txtNAME.Text = "" + EmpName + "";
                txtDEPARTMENT.Text = "" + Department + "";
            }
            {
                DateTime currentDate = DateTime.Now;
                List<ListItem> items = new List<ListItem>();
                items.Add(new ListItem
                {
                    Text = currentDate.AddMonths(-1).Month.ToString(),
                    Value = currentDate.AddMonths(-1).Month.ToString()
                });
                items.Add(new ListItem
                {
                    Text = currentDate.Month.ToString(),
                    Value = currentDate.Month.ToString()
                });
                ddl_Month.DataSource = items;
                ddl_Month.DataTextField = "Text";
                ddl_Month.DataValueField = "Text";
                ddl_Month.DataBind();
            }
        }
        protected void Insert(object sender, EventArgs e)
        {
            string EMPNO = txtEMPNO.Text;
            string NAME = txtNAME.Text;
            string DEPARTMENT = txtDEPARTMENT.Text;
            string Year = ddl_Year.Text;
            string Month = ddl_Month.Text;
            string DATE = txtDATE.Text;
            string INDICATER_TYPE = DropDownList2.Text;
            string INDICATER_Desc = DropDownList3.Text;
            string COMPLIED = DropDownList1.Text;
            string REMARK = txtREMARK.Text;
            DropDownList2.Text = "";
            DropDownList3.Text = "";
            DropDownList1.Text = "";
            txtREMARK.Text = "";
            string query = "INSERT INTO lead_lag VALUES(@EMPNO,@NAME, @DEPARTMENT,@Year,@Month,@DATE,@INDICATER_TYPE,@INDICATER_Desc,@COMPLIED,@REMARK,@flag )";
            string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
            using (SqlConnection con = new SqlConnection(constr))
            {
                using (SqlCommand cmd = new SqlCommand(query))
                {
                    cmd.Parameters.AddWithValue("@EMPNO", EMPNO);
                    cmd.Parameters.AddWithValue("@NAME", NAME);
                    cmd.Parameters.AddWithValue("@DEPARTMENT", DEPARTMENT);
                    cmd.Parameters.AddWithValue("@Year", Year);
                    cmd.Parameters.AddWithValue("@Month", Month);
                    cmd.Parameters.AddWithValue("@DATE", DATE);
                    cmd.Parameters.AddWithValue("@INDICATER_TYPE", INDICATER_TYPE);
                    cmd.Parameters.AddWithValue("@INDICATER_Desc", INDICATER_Desc);
                    cmd.Parameters.AddWithValue("@COMPLIED", COMPLIED);
                    cmd.Parameters.AddWithValue("@REMARK", REMARK);
                    cmd.Parameters.AddWithValue("@flag", "");
                    cmd.Connection = con;
                    con.Open();
                    cmd.ExecuteNonQuery();
                    con.Close();
                }
            }
            this.BindGrid();
        }
        protected void chkSelectAll_CheckedChanged(object sender, EventArgs e)
        {
            CheckBox chkAll = (CheckBox)GridView1.HeaderRow.FindControl("chkSelectAll");
            foreach (GridViewRow gvRow in GridView1.Rows)
            {
                CheckBox chkSel = (CheckBox)gvRow.FindControl("chkSelect");
                if (
                    chkAll.Checked)
                {
                    chkSel.Checked = true;
                }
                else
                {
                    chkSel.Checked = false;
                }
            }
        }
    }