javascript - Request.QueryString is undefined -

i using following code logedinuser login.aspx , send chat.aspx send frmforajaxcalls return data db , fill on div in running time telling me in browser console request.querystring undefined

here login.aspx code

protected void button3_click(object sender, eventargs e) {      response.redirect("chat.aspx?lgn2="+textboxusername.text); } 

and chat.aspx javascript code

<script type="text/javascript" >     var xmlhttp;      function getdata() {         xmlhttp = null;         if (window.xmlhttprequest) {             xmlhttp = new xmlhttprequest();         }         else if (window.activexobject) {             xmlhttp = new activexobject();         }                   string logedinuser = request.cookies["logedinuser"].value;           var logedinuser = request.querystring["lgn2"];          xmlhttp.onreadystatechange = function () {              if (xmlhttp.readystate == 4 || xmlhttp.status == 200) {                  document.getelementbyid("mydiv").innerhtml = xmlhttp.responsetext;             }         }         xmlhttp.open("get", "frmforajaxcalls.aspx?lgn=" + logedinuser, true);         xmlhttp.send();     } 

then send frmforajaxcalls return data return nothing on div request.querystring undefined exption on browser console

 protected void page_load(object sender, eventargs e) {     string logedinuser = request.querystring["lgn2"].tostring();      stringbuilder html = new stringbuilder();          string result = string.empty;         sqlconnection cnn = new sqlconnection(configurationmanager.connectionstrings["crconnection"].connectionstring);         sqlcommand cmd = new sqlcommand("select messagenum , message , sendername ,date message reciverusername='" + logedinuser + "'", cnn);         cnn.open();         sqldataadapter da = new sqldataadapter(cmd);         datatable dt = new datatable();         da.fill(dt);         html.append("<div id = xxx> ");         html.append("<table border='1'>");         html.append("<tr>");         foreach (datacolumn col in dt.columns)         {             html.append("<th>");             html.append(col.columnname);             html.append("</th>");         }         html.append("</tr>");         foreach (datarow row in dt.rows)         {             html.append("<tr>");             foreach (datacolumn col in dt.columns)             {                 html.append("<td>");                 html.append(row[col.columnname]);                 html.append("</td>");             }             html.append("</tr>");         }         html.append("</table>");         html.append("</div>");          response.write(html);  } 

in paste chat.aspx, you're calling lgn instead of lgn2... all? in situations this, first mission should add logging throughout process see falls apart, can pinpoint problem is.