How to call jQuery code only before the ASP.NET postback

"PostBack is the name given to the process of submitting an ASP.NET page to the server for processing ."

protected void Page_Load(object sender, EventArgs e)

{

   if (IsPostBack)

   {

        ClientScript.RegisterHiddenField("hdnPostBack", "1");

   }

 }




$(document).ready(function () {

    var isPostBackOccured = document.getElementById('hdnPostBack');

    if (isPostBackOccured== null) alert('Page is called first Time');

    else alert('Page is called after Postback');

});