Details:
AJAX type web forms perform partial page updates made by an UpdatePanel on the page.
Code like $(document).ready(function(){}); will only be executed once after the page Document Object Model (DOM) is ready for JavaScript code to execute.
Solution:
If you want to execute JavaScript code after each partial update, use the MSAjax pageLoad Event in your Javascript code:
<script>
// To ensure JavaScript is executed in runtime mode only.
if (typeof $selectedObject === "undefined")
{
///<summary>
/// This will fire on initial page load,
/// and all subsequent partial page updates made
/// by any update panel on the page
///</summary>
function pageLoad(){ alert('page loaded!')}
}
</script>