Error 'An object reference is required for the non-static field, method, or property' on Ajax call in ASP.Net

There is two calendars , one drop down and one grid view and button. Now i try to access these ID's on server side

<asp:DropDownList ID="regiondrop" runat="server" AutoPostBack="True"
    onselectedindexchanged="regiondrop_SelectedIndexChanged">
    </asp:DropDownList>
 <input  ID="fromdate" value="dd/mm/yyyy" runat="server" clientidmode="static" />
  <input  ID="todate" value="dd/mm/yyyy" runat="server" clientidmode="static" />
<input type="button" id="search_data"    class="sear_btn"  value="Search Data"  />

and gridview

now i try to display grid view on page

for this i try this

<script type="text/javascript">
 $(function () {

         var fromdate = $('[ID*=fromdate]').val();
         var todate = $('[ID*=todate]').val();
         var regiondrop = $('[ID*=regiondrop] option:selected')[0].value;
         var GridView1 = $('[ID*=GridView1]');
         var obj = {};
         obj.fromdate = todate ;
         obj.todate = todate ;
         obj.regiondrop = regiondrop ;
         obj.GridView1 =GridView1 ;
         Getdataa(obj);
         return false;

 });
 function Getdataa(obj) {
     //alert('1');
     $.ajax({
         type: "POST",
         url: "WebForm1.aspx/search_data",
         data: "{'fromdate':'" + fromdate + "','todate':'" + todate + "','regiondrop':'" + regiondrop + "','GridView1':'" + GridView1 + "'}",
         contentType: "application/json; charset=utf-8",
         dataType: "json",
         async: true,
         cache: false,
         success: function (result) {
             $("#GridView1").empty();
             if(data.d.length>0){
             $("#GridView1").append(
             "<tr><th>OName</th><th>RegNo</th>><th>Speed</th>");

             for(var i=0;i<data.d.length;i++){
             $("#GridView1").append("<tr><td>" + 
             data.d[i].OName + "</td> <td>" + 
             data.d[i].RegNo + "</td> <td>" + 
             data.d[i].Speed + "</td></tr>");
                }
            }   
         },
         error: function (error) {
             alert("error");

         }
     });
 }

For access ID's i try to get ID and then i pass these ID in webmethod function like ths

[WebMethod]
    public static string search_data(DateTime fromdate, DateTime todate, string regiondrop)
    {

        try
        {

            DateTime frmdate = 
           Convert.ToDateTime(fromdate.Value.Trim().Split('T')[0]);
            DateTime tdatee = 
            Convert.ToDateTime(todate.Value.Trim().Split('T')[0]);
            string regionvalue = Convert.ToString(regiondrop.SelectedValue);
            T1 ts = new T1();

            // here dq code is like this var dq= and here i write LINQ query  
            //i don't paste because of long query 
            GridView1.DataSource = dq;
            GridView1.DataBind();

        }
        catch (Exception)
        {
            GridView1.Visible = false;
            Label4.Text = ("No Data");

        }

    }

when i try this show errors

Error 2 'System.DateTime' does not contain a definition for 'Value' and no extension method 'Value' accepting a first argument of type 'System.DateTime' could be found (are you missing a using directive or an assembly reference?)

Error 3 'System.DateTime' does not contain a definition for 'Value' and no extension method 'Value' accepting a first argument of type 'System.DateTime' could be found (are you missing a using directive or an assembly reference?)

Error 4 'string' does not contain a definition for 'SelectedValue' and no extension method 'SelectedValue' accepting a first argument of type 'string' could be found (are you missing a using directive or an assembly reference?)

Error 5 An object reference is required for the non-static field, method, or property 'chart_project.WebForm1.GridView1'

Error 8 An object reference is required for the non-static field, method, or property 'chart_project.WebForm1.Label4'

any solution