Button Click Event after deployment

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C#3.0

C#

I have a small web application which is running well on my local machine but once I deploy my site to the server, all the other buttons click events are working except for one button event which is not firing:

public void checkpassword(object sender,EventArgs e)
   {

       string password = txtpassword.Text.ToString();
       SqlConnection con = new SqlConnection(connect);
       SqlCommand command = new SqlCommand("matchpassword",con);
       con.Open();
       command.CommandType = CommandType.StoredProcedure;

       SqlDataAdapter sqlDALogin1 = new SqlDataAdapter();
       DataSet sqlDSLogin1 = new DataSet();
       sqlDALogin1.SelectCommand = command;
       sqlDALogin1.Fill(sqlDSLogin1, "Password");

       string passwrd = Convert.ToString(sqlDSLogin1.Tables[0].Rows[0]["Password"]);
       con.Close();

       if (password == passwrd)
       {

       }
       else
       {
           //Response.Redirect("ViewRecords.aspx");
           lbldisplay.Text = "Wrong Password";
           panelpassword.Update();
           ModalPassword.Show();
       }

   }

<asp:Panel ID="Panel1" runat="server" CssClass="HellowWorldPopup2" Style="display:none">
             <asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
                 <ContentTemplate>

                     <asp:Button ID="BtnOK" runat="server" Text="OK" CssClass="lb-testright" OnClick="checkpassword"
                       />
                     <asp:Button ID="BtnCancel" runat="server" Text="Cancel" CssClass="lb-testleft" OnClick="redirecttorecords" />
                      <asp:Button ID="Button1" runat="server" Text="Cancel" Style="display:none" />
                     <asp:Label ID="Label2" runat="server" Text="Label"></asp:Label>
                     <asp:TextBox ID="txtpassword" runat="server" CssClass="lb-textbox"
                         TextMode="Password" onfocus="clearContents(this);">Password </asp:TextBox>

             <asp:ModalPopupExtender ID="Modal_Password" runat="server"
               TargetControlID="Button1" PopupControlID="Panel1" DropShadow="true" >
             </asp:ModalPopupExtender>
             </ContentTemplate>
             </asp:UpdatePanel>
        </asp:Panel>

This is working fine on my machine but what doesn't work when deployed.
Thanks