Hi  maideen,
Refer the below sample.
HTML
<asp:Panel runat="server" ID="pnl_btns">
</asp:Panel>
C#
protected void Page_Load(object sender, EventArgs e)
{
    string query = string.Format("SELECT roomno from AD_Rooms_Master order by roomno");
    try
    {
        DataTable dt = GetData(query);
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            Button btn = new Button();
            btn.ID = "btn" + (i + 1);
            btn.Text = dt.Rows[i]["roomno"].ToString();
            btn.Click += btnLoadButton_Click;
            pnl_btns.Controls.Add(btn);
        }
    }
    catch (Exception ex)
    {
        ScriptManager.RegisterStartupScript(this, this.GetType(), "Message", "alert('Error occured : " + ex.Message.ToString() + "');", true);
    }
    finally
    {
        //cmd = null;
        //conn.Close();
    }
}
protected void btnLoadButton_Click(object sender, EventArgs e)
{
    ClientScript.RegisterClientScriptBlock(this.GetType(), "button", "<script type = 'text/javascript'>alert('Room no " + (sender as Button).Text + " selected');</script>");
}
VB.Net
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    Dim query As String = String.Format("SELECT roomno from AD_Rooms_Master order by roomno")
    Try
        Dim dt As DataTable = GetData(query)
        For i As Int32 = 0 To dt.Rows.Count - 1
            Dim btn As New Button()
            btn.ID = "btn" & (i + 1)
            btn.Text = dt.Rows(i)("roomno").ToString()
            AddHandler btn.Click, AddressOf btnLoadButton_Click
            pnl_btns.Controls.Add(btn)
        Next
    Catch ex As Exception
        ScriptManager.RegisterStartupScript(Me, Me.[GetType](), "Message", "alert('Error occured : " + ex.Message.ToString() + "');", True)
    Finally
    End Try
End Sub
Protected Sub btnLoadButton_Click(sender As Object, e As EventArgs)
    ClientScript.RegisterClientScriptBlock(Me.[GetType](), "button", "<script type = 'text/javascript'>alert('Button " + TryCast(sender, Button).Text + " clicked');</script>")
End Sub
Screenshot
