Update panel uses asp.net recall the script function

 <script type="text/javascript">

$(function () {

    Sys.WebForms.PageRequestManager.getInstance().add_pageLoaded(yourown);

});

function yourown() 

{

alert();

}

</script>

Use update panel in asp.net page button click (or) postback events at the time some script fuction recall usage at time this script using for usfully to recall the fuction .