How to Change Aajax Controls tool kit by Cleint Side?

you can change any of page controls in client side by knowing the id of the control by viewing the source in the browser in the page runtime. once you get the id of the control, whatever it was select control or input control you can change the value like
 
document.getElementById("controlRealIdFetchedInRunTime").value = "some value";
 
if it helps you mark as solved.