error

please look my code
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

namespace SchoolManagement.Designs
{
    public partial class Division : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            MultiView1.SetActiveView(View1);
            combofill();
            gridfill();
        }
        public void combofill()
        {

            ClassSP spClass = new ClassSP();
            DataTable dtblc = new DataTable();
            dtblc = spClass.classViewAll();
            ddlname.DataSource = dtblc;
            ddlname.DataValueField = "classId";
            ddlname.DataTextField = "className";
            ddlname.DataBind();
            ddlname.Items.Insert(0, "--select--");

        }
        public void gridfill()
        {
            DivisionInfo infodivision = new DivisionInfo();
            DivisionSP spdivision = new DivisionSP();
            DataTable dtbl = new DataTable();
            dtbl = spdivision.divisionViewAll();
            GridView1.DataSource = dtbl;
            GridView1.DataBind();
           

        }

        protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
        {
            GridView1.PageIndex = e.NewPageIndex;
            gridfill();
        }
        public void clear()
        {
            txtdiv.Text = string.Empty;
            ddlname.SelectedIndex = 0;
        }

        protected void btnclear_Click(object sender, EventArgs e)
        {
            clear();
        }

        protected void btnsave_Click(object sender, EventArgs e)
        {
            if (ddlname.SelectedIndex != 0 && txtdiv.Text != string.Empty)
            {
                DivisionInfo infodivision = new DivisionInfo();
                infodivision.classId = decimal.Parse(ddlname.SelectedValue.ToString());
                infodivision.divisionName = txtdiv.Text.Trim();
                DivisionSP SPDivision = new DivisionSP();
                if (btnsave.Text == "Save")
                {
                    SPDivision.divisionAdd(infodivision);
                    Response.Write("");
                    gridfill();
                }
            }

        }
    }
}
when i click the button save

it will say plese select the field
my aspx code is
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Division.aspx.cs" Inherits="SchoolManagement.Designs.Division" %>

<%@ Register src="../WebUserControl1.ascx" tagname="WebUserControl1" tagprefix="uc1" %>





   
   
   


   

   

   

Division

   

   

   
    

Upcoming Events

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	ControlToValidate="ddlname" ErrorMessage="*" InitialValue="--select--"                                 ToolTip="Please select the ClassName" ValidationGroup="a">
	ControlToValidate="txtdiv" Display="Dynamic" ErrorMessage="*"                                 ToolTip="Enter the divisionName" ValidationGroup="a">

               

                                           
                                    onclick="btnsave_Click" />
                        
                                    onclick="btnclear_Click" />
               

               

               

               

                       

Division

                                            AllowPaging="True" onpageindexchanging="GridView1_PageIndexChanging">