Check Postback in Javascript

function isPostBack() {
return document.referrer.indexOf(document.location.href) > -1;
}

Sharepoint people picker Validation

Sharepoint People picker validation in javascript

var validatorId = 'validator ID';
        var textboxId = validatorId.replace('val_pck', 'txt_pck');
         var pickerId = validatorId.replace('val_pck', 'pck');
         var pickerValue = $("#" + pickerId).html();
         if (pickerValue == "" || pickerValue.indexOf('title') == -1 || $("

" + pickerValue + "

").find("#divEntityData").length == 0)
         {
          alert('invalid');
         }

set the value of people picker

var pickerKey = $("

"

 + pickerValue + "

").find("#divEntityData").attr("key");
if (args.IsValid && $('#' + textboxId)) $('#' + textboxId).val(pickerKey);

POST Method in XMLHTTP Request in Sharepoint

function callAjax() {


var messageContent = "Text9";

var params = "MessageContent=" + messageContent;
alert(params);

//ajax to check length
var xmlHTTPObject = new ActiveXObject("Microsoft.XMLHTTP");
if (xmlHTTPObject == null) return null;
xmlHTTPObject.Open("POST", "http://localhost:51240/WebSite1/Ajax.aspx", true);
//alert('/sites/MB/_layouts/MB2010/MBCheckMessageSize.aspx');

xmlHTTPObject.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");

// xmlHTTPObject.setRequestHeader('Content-Type', 'application/text; charset=utf-8');

xmlHTTPObject.setRequestHeader('Content-length', params.length);

///xmlHTTPObject.setRequestHeader('Connection', "close");
//alert("/_layouts/AMAT.MOLDS/GetMoldPartNo.aspx?MatNo="+partNumberVal);

xmlHTTPObject.onreadystatechange = function () {

if (xmlHTTPObject.readyState == 4 && xmlHTTPObject.status == 200) {

// alert(a.responseText);
if (xmlHTTPObject.responseText.length > 0) {

alert(xmlHTTPObject.responseText);

}

else {

//alert("Else Block");
}

}

}

//alert(d);

xmlHTTPObject.Send(params);
}

CS Page Code
Request.Form["MessageContent"];