Changing table column size

alter table table_name alter column column_name char(500)

How to restrict textbox to enter 500 characters only after that if we insert any character it will display pop up message

Design page
<asp:TextBox ID="txtreqtitle" runat="server" CssClass="textCopy" Width="260px" Columns="25"
 MaxLength="500" TextMode="MultiLine"  Rows="3" Height="55px"  ></asp:TextBox>

aspx.cs page
this.txtreqtitle.Attributes.Add("onKeyPress", "return textCounter(this, 500);");
this.txtreqtitle.Attributes.Add("onKeyUp", "return textCounter(this, 500);");

javascript on radio button click

 <script type="text/javascript">

function Enable_PromProg() {
            debugger;
            var rdbPromProgYes = document.getElementById("<%=rdbPromProgYes.ClientID%>");
            var rdbPromProgNo = document.getElementById("<%=rdbPromProgNo.ClientID%>");
            var trPromotional = document.getElementById("<%=trPromotional.ClientID%>");
            if (rdbPromProgYes != null) {

                trPromotional.style.display = 'none';
                if (rdbPromProgYes.checked != true && rdbPromProgNo.checked != true) {

                    trPromotional.style.display = 'none';
                    //txtPromotionalDesc.disabled = true;
                }
                else if (rdbPromProgYes.checked == true) {
                    trPromotional.style.display = '';
                    //txtPromotionalDesc.disabled = false;
                }
                else if (rdbPromProgNo.checked == true) {

                    trPromotional.style.display = 'none';
                }
            }
        }


</script>

<asp:RadioButton ID="rdbPromProgYes" runat="server" Text="Yes" GroupName="PromProg"
                                                onclick="javascript:Enable_PromProg();" />

Case statement in SQL

"PaymentReleaseDate"=
Case ISNULL(Convert(Varchar(20),tgr.ap_print_date,101),'') when '' then
( Select milestone_release_date from t_grant_milestones where grant_id= tgr.grant_id and entry_id=tgm.entry_id)
else tgr.ap_print_date 
End AS  PaymentReleaseDate,

Query String in ASP.Net

pass the value through url from previous page
 int FromID = Convert.ToInt32(Session["User_Id"]);
 string url = "EmployeeDetails.aspx?From_ID=" + FromID.ToString();
 Response.Redirect(url);

Accept the value which passed by url 

 string From_ID = Request.QueryString["From_ID"].ToString();

view Delivery formate usage

Create view [dbo].[Vw_Delivery_format_usage]
as

Select distinct grant_id,delivery_format_name,approved_amount,date_submitted From (

Select t1.grant_id,
case when t1.TotalValue=1 then tad.delivery_format_name
else 'MultiView'
end as delivery_format_name
,approved_amount
,g.date_submitted,TotalValue
From (
Select COUNT(delivery_format_name) as TotalValue,grant_id from (
        select
        distinct a.grant_id,
        tad.delivery_format_name,
        g.approved_amount
        from t_grant_request g
        inner join t_grant_activity a on a.grant_id=g.grant_id
        inner join t_activity_delivery_format tad on tad.delivery_format_id=a.delivery_format_id
)t
group by grant_id
)t1 inner join
t_grant_request g on t1.grant_id=g.grant_id
inner join t_grant_activity a on a.grant_id=g.grant_id
and g.approved_amount is not null
and approved_amount not in (0) 
and g.grant_status not in ('not submitted','cancelled','denied','rejected')
inner join t_activity_delivery_format tad on tad.delivery_format_id=a.delivery_format_id
)t2

return url issue

add this code to the global.asax page

void Application_BeginRequest(object sender, EventArgs e)
   {
       string path = HttpContext.Current.Request.Url.PathAndQuery;
       string pagequery = path.Substring(path.LastIndexOf("/") + 1);
       string[] pagequery_Elements = pagequery.Split('?');
       string ReturnUrl = pagequery_Elements[pagequery_Elements.Length - 1];

       if (ReturnUrl.Contains("ReturnUrl"))
       {        
           Response.Redirect("~/login.aspx", true);
       }
   }