Post Data on asp.net Page using Javascript/Jquery

Method : Post

function AjaxCalltoPostData(datastring) {
    var xmlhttp;
    var responsestring;
    if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp = new XMLHttpRequest();
    }
    else {// code for IE6, IE5
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    xmlhttp.onreadystatechange = function () {
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                  responsestring = xmlhttp.responseText;
         }
    }
    var data = "content=" + datastring;
    xmlhttp.open("POST", "TempPage.aspx", true);
    xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    xmlhttp.send(data);

}

On Page Load of TempPage.aspx Get Data using :
string content = Request["content"];
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Method : Get

 function AjaxCallUsingGetMethod() {
        var xmlhttp;
        var responsestring;
        if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
            xmlhttp = new XMLHttpRequest();
        }
        else {// code for IE6, IE5
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        xmlhttp.onreadystatechange = function () {
            if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {         
                responsestring= xmlhttp.responseText;   
            }
        }
        xmlhttp.open("GET", "TempPage.aspx?func=getdata&source=" + $('#txtsource').val() + "&dest=" + $('#txtdestination').val() + "&fdate=" + $('#datetoday').val() + "", true);
        xmlhttp.send();

    }

On Page Load of TempPage.aspx Get Data using :

  string funname = Convert.ToString(Request.QueryString["func"]);
            if ((funname  + "").Trim().ToLower() == "getdata")
            {
                string src = Convert.ToString(Request.QueryString["source"]);
                string dest = Convert.ToString(Request.QueryString["dest"]);
                DateTime fdate = Convert.ToDateTime(Request.QueryString["fdate"]);
                string xmlres = GetDataFromASPFunc(src, dest, fdate);
                Response.Write(xmlres);
            }