This will display the server side control name which is used for jquery

alert($("[id$=TextBoxTest]").attr("id"));

If you use Telerik, it will display ‘ctl00_ContentPlaceHolder1_CostOfTraining1_TextBoxTest’ when calling Telerik server side control from client side. Then you can use it to do anything at client side like:

$(‘#ctl00_ContentPlaceHolder1_CostOfTraining1_TextBoxTest’).keyup(function(event) {
Do something();
});