Hi ,
i read data to 3 combos - 2 of them depend on other . I don't know how to do another callback to the third DDL - it causes some problems.

hi there.. do you have some code?? or any specific problem???

HTH

Gonzalo

Hi ,
here is the javascript code in .aspx file :
   <script language="javascript">
   function ClientCallback(result, context){

      var childOrganizations = document.forms[0].elements[
            '<%=ddlSubCat.UniqueID%>'];

      if (!childOrganizations){
         return;
      }
      childOrganizations.length = 0;
      if (!result){
         return;
      }
      grp = result.split("~")[1];
      result = result.split("~")[0];
      var rows = result.split('|');
      for (var i = 0; i < rows.length; ++i){

         var values = rows[i].split('^');
         var option = document.createElement("OPTION");
         option.value = values[0];
         option.innerHTML = values[1];
         if (option != undefined && values[1] != undefined && values[0] != undefined) {
         childOrganizations.appendChild(option);
         }
        //childOrganizations.options.add(option , i);
      }
       var childGrp = document.forms[0].elements[
       '<%=ddlGroup.UniqueID%>'];
       childGrp.length = 0;
       var rows1 = grp.split('|');
       for (var j = 0; j < rows1.length; ++j){
         var values1 = rows1[j].split('^');
         var option1 = document.createElement("OPTION");
         option1.value = values1[0];
         option1.innerHTML = values1[1];
         if (option1 != undefined && values1[1] != undefined && values1[0] != undefined) {
         childGrp.appendChild(option1);
         }
      }


   }

      function ClientCallback1(result, context){

       var childGrp = document.forms[0].elements[
       '<%=ddlGroup.UniqueID%>'];
       childGrp.length = 0;
       var rows1 = result.split('|');
       for (var j = 0; j < rows1.length; ++j){
         var values1 = rows1[j].split('^');
         var option1 = document.createElement("OPTION");
         option1.value = values1[0];
         option1.innerHTML = values1[1];
         if (option1 != undefined && values1[1] != undefined && values1[0] != undefined) {
         childGrp.appendChild(option1);
         }
        //childOrganizations.options.add(option , i);
      }

   }

   function GetChildren(arg, context)
   {

   <%= callBack %>
    }

      function GetSubChildren(arg, context)
   {

   <%= callBack1 %>
   }
   </script>


AND here is part of the .aspx.cs file code :
public partial class BookPhone : System.Web.UI.Page , ICallbackEventHandler
{
    public string callBack , callBack1;
    public int choice = 1;
    int arg = 0 , arg3 = 0 ;

    protected void Page_Load(object sender, EventArgs e)
    {


        //Response.Write("<script language='JavaScript'>alert('" + Request.Cookies["PUID"].Value + "');</script>");
        /*if (Request.Cookies["PUID"] == null || Request.Cookies["PUID"].Value.Trim().Equals(""))
        {
            Response.Redirect("default.aspx");
        }
        if (!new UserOwnBooksController().IsUserOwnsBooks(Request.C ookies["PUID"].Value , TryParse(Request.QueryString["BID"])))
        {
            Response.Redirect("default.aspx");
        }*/
        DataRow dr = new BooksController().GetSpecificBook(int.Parse(Reques t.QueryString["BID"]));
            lblCount2.Text = new PhoneController().GetNumOfRecords(int.Parse(Reques t.QueryString["BID"])).ToString();
        //imgPrint1.OnClientClick = "OpenPopUp('" + Request.QueryString["BID"] + "' , '" + txtSearchWords.Text.Trim() + "' , '" + ddlCat111.SelectedValue + "' , '" + ddlSubCat111.SelectedValue + "' , '" + ddlGroup111.SelectedValue + "');";
            imgPrint1.PostBackUrl = "PrintScreen.aspx?BID=" + Request.QueryString["BID"] + "&KID=" + txtSearchWords.Text.Trim() + "&CatID=" + ddlCat111.SelectedValue + "&SID=" + ddlSubCat111.SelectedValue + "&GID=" + ddlGroup111.SelectedValue + "";
        if (!Page.IsPostBack)
        {
            PopulateBirthDate();
            PopulateSearch();


        }
        if (dr != null)
        {
            lblHeader1.Text = dr[1].ToString();
        }
        foreach (GridViewRow gr in GridView1.Rows) {
            DataRow dr1 = new PhoneController().GetSpecificRow(TryParse(Request. QueryString["BID"]));
        if (dr1 != null)
        {
            gr.ForeColor = System.Drawing.Color.FromName(dr1[26].ToString());
            gr.Font.Size = new FontUnit(dr1[25].ToString());
            gr.Font.Name = dr1[24].ToString();
        }
        }

        callBack = Page.ClientScript.GetCallbackEventReference(this, "arg" , "ClientCallback", "context");
        callBack1 = Page.ClientScript.GetCallbackEventReference(this, "arg", "ClientCallback1", "context");

        ddlCat.Attributes.Add("onchange", "GetChildren(this.options[this.selectedIndex].value, 'ddlSubCat');");
        ddlSubCat.Attributes.Add("onchange", "GetSubChildren(this.options[this.selectedIndex].value , 'ddlGroup')");

    }

    public void RaiseCallbackEvent(string eventArgument)
    {
        if (choice == 1)
        {
            int parentId;

            if (Int32.TryParse(eventArgument, out parentId))
            {
                int firstNum = -1000;
                DataTable dt = new BSubCatsController().GetSubCatsByBookAndCat(int.Pa rse(Request.QueryString["BID"]), int.Parse(eventArgument));
                StringBuilder sb = new StringBuilder();
                for (int i = 0; i < dt.Rows.Count; ++i)
                {
                    sb.Append(dt.Rows[i]["SubCatID"]);
                    sb.Append("^");
                    sb.Append(dt.Rows[i]["SubCatDescription"]);
                    sb.Append("|");
                    if (firstNum == -1000)
                    {
                        firstNum = (int)dt.Rows[i]["SubCatID"];
                    }
                }
                sb.Append("~");
                arg = int.Parse(eventArgument);
                DataTable dt1 = new BGroupsController().GetGroupByBookCatAndSubCat(int .Parse(Request.QueryString["BID"]), arg, firstNum);
                foreach (DataRow dr1 in dt1.Rows)
                {
                    sb.Append(dr1["GroupID"]);
                    sb.Append("^");
                    sb.Append(dr1["GroupDesc"]);
                    sb.Append("|");
                }

            }
        }
        else if (choice == 2)
        {
            StringBuilder sb1 = new StringBuilder();
            arg3 = int.Parse(eventArgument);
            int theNum = arg3 ;
            DataTable dt3 = new BGroupsController().GetGroupByBookCatAndSubCat(int .Parse(Request.QueryString["BID"]), arg, theNum);

            foreach (DataRow dr3 in dt3.Rows)
            {
                sb1.Append(dr3["GroupID"]);
                sb1.Append("^");
                sb1.Append(dr3["GroupDesc"]);
                sb1.Append("|");
            }
        }
    }


    public string GetCallbackResult()
    {
        if (choice == 1)
        {
            int firstNum = -1000;
            DataTable dt = new BSubCatsController().GetSubCatsByBookAndCat(int.Pa rse(Request.QueryString["BID"]), arg);
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < dt.Rows.Count; ++i)
            {
                sb.Append(dt.Rows[i]["SubCatID"]);
                sb.Append("^");
                sb.Append(dt.Rows[i]["SubCatDescription"]);
                sb.Append("|");
                if (firstNum == -1000)
                {
                    firstNum = (int)dt.Rows[i]["SubCatID"];
                }
            }
            sb.Append("~");
            DataTable dt1 = new BGroupsController().GetGroupByBookCatAndSubCat(int .Parse(Request.QueryString["BID"]), arg, firstNum);
            foreach (DataRow dr1 in dt1.Rows)
            {
                sb.Append(dr1["GroupID"]);
                sb.Append("^");
                sb.Append(dr1["GroupDesc"]);
                sb.Append("|");
            }
            return sb.ToString();
        }
        else if (choice == 2)
        {

            StringBuilder sb1 = new StringBuilder();
            DataTable dt3 = new BGroupsController().GetGroupByBookCatAndSubCat(int .Parse(Request.QueryString["BID"]), arg, arg3);
            foreach (DataRow dr3 in dt3.Rows)
            {
                sb1.Append(dr3["GroupID"]);
                sb1.Append("^");
                sb1.Append(dr3["GroupDesc"]);
                sb1.Append("|");
            }
            return sb1.ToString();

        }
        return "";

    }

if this code is not sufficient - i'll send you the files to email.

i don't have a clue about js, sorry...

you are doing the callbacks with js?

HTH

Gonzalo