I have given reference of Ajax.dll in my project. there are 2 dropdownlist boxes (one is for country and other one is for State) in one form. they are interrelated means if i select any country, depends on that i will get states's list in my other dropdownlistbox.


This is code is working...

 I writed down code in sample.aspx page:

<script language="javascript" type="text/javascript">
<!--
   function ClientGetStates(ddlCountry)
   {
    var countryId = ddlCountry.options[ddlCountry.selectedIndex].value;
    if (countryId > 0)
       {
PresentationLayer_JobSeeker_frmJobSeekerRegistrati on.GetStates(countryId,LoadStates_CallBack

);
        }
    }


       function LoadStates_CallBack(response)
        {
            if (response.error != null)
                {
                    alert(response.error);
                    return;
                }

            var states = response.value;
            if (states == null || typeof(states) != "object")
                {
                    return;
                }
            var statesList = document.getElementById("ddlState");
            statesList.options.length=0;
            for (var i = 0; i < states.length; ++i)
                {
                    statesList.options[statesList.options.length] = new

Option(states[i].State_Name, states[i].State_ID);
                }
        }

// -->
</script>


    <select id="ddlCountry" language="javascript" onchange="ClientGetStates(this)"

runat="server"> </select>

       <select id="ddlState" datatextfield="State_Name" datavaluefield="State_ID"

language="javascript"></select>



In Sample.aspx.cs File:


  protected void Page_Load(object sender, EventArgs e)
    {
       Ajax.Utility.RegisterTypeForAjax(typeof(Sample));
    }

    [Ajax.AjaxMethod()]
    public static DataView GetStates(Int32 iCountryIndex)
    {
        System.Data.DataView dv = new

System.Data.DataView(((DataTable)ParamState.ShowSe lected(iCountryIndex).Tables[0]));
        return dv;

    }


I want to run ddlState on server means (runat=server). at that time i m writing this code but this code is not running. can u suggest if i want to run this further code want to be run that what should i have to do.
This is not working ....



<script language="javascript" type="text/javascript">
<!--
   function ClientGetStates(ddlCountry)
   {
    var countryId = ddlCountry.options[ddlCountry.selectedIndex].value;
    if (countryId > 0)
       {
PresentationLayer_JobSeeker_frmJobSeekerRegistrati on.GetStates(countryId,LoadStates_CallBack

);
        }
    }

       function LoadStates_CallBack(response)
        {
            if(response.value == true)
                {
                    alert("You have changed");
                }
        }


// -->
</script>


    <select id="ddlCountry" language="javascript" onchange="ClientGetStates(this)"

runat="server"> </select>

      <select id="ddlState" datatextfield="State_Name" datavaluefield="State_ID"

runat="server"> </select>


In Sample.aspx.cs File:


  protected void Page_Load(object sender, EventArgs e)
    {
       Ajax.Utility.RegisterTypeForAjax(typeof(Sample));
    }

    [Ajax.AjaxMethod()]
    public static bool GetStates(Int32 iCountryIndex)
    {

        ddlState.Items.Clear();
        ddlState.DataSource = ParamState.ShowSelected(iCountryIndex).Tables[0].DefaultView;
        ddlState.DataTextField = "State_Name";
        ddlState.DataValueField = "State_ID";
        ddlState.DataBind();
        return true;
    }