where to get the data posted from the client?

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
public partial class ResponseTest : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
       
        var a = Request; //I didn't find the data in Request's structure.
        Response.Write("successed; hello World;");
    }
}
 
 
//-----------------------javascript--------------
for( var i=0; i<this.dataToBeSent.length && t ...