Hi everyone,

I am trying to create conrol dynamically. i am using the following
code..inside pageload

if (!IsPostBack)
        {
            string qry_fwd = qry.Substring(qry.IndexOf("and"));
            Session["qry_fwd"] = qry_fwd;

            qry = qry.Substring(0, qry.IndexOf("and"));


            // for checking the type of qyery..

            flag = checkqry_type(qry);


                if (flag == true)
                {


                    int k = qry.LastIndexOf(">");

                    string qry_CreateControl = qry.Remove(k + 1);

                    string qry_execute = qry.Remove(0, k + 1);


                    ControlDef(qry_CreateControl,
PlaceHolderControls);
                    ExtractControls();


                }
                else
                {
                    //WebPortalReporting.ControlDef c = new
ControlDef(qry, PlaceHolderControls);
                    ControlDef(qry, PlaceHolderControls);
                    ExtractControls();
                    Session["qry"] = qry;
                }


            ////if second type of query

        }
        else
        {
            string qry_fwd = Session["qry_fwd"].ToString();
            qry_fwd = qry_fwd.Substring(0,
qry_fwd.IndexOf("completion"));

            ControlDef(qry_fwd, PlaceHolderControls);
            ExtractControls();
        }



but when ever a button is pressed i get the following error-


"Invalid postback or callback argument.

Event validation is enabled using <pages enableEventValidation="true"/

> in configuration or


<%@ Page EnableEventValidation="true" %> in a page.


i have tried to solve the problem by sdetting the value of Page
EnableEventValidation to false.but it also gives an error -"parameter
name can not be null"

Please sujjest  a way to proceed.

Thanks in advance,
Arnab