$(document).ready(function() {
    $("[id$='_txtClientName']").focus();

});

var requestMgr = Sys.WebForms.PageRequestManager.getInstance();

requestMgr.add_initializeRequest(InitializeRequest);
requestMgr.add_endRequest(EndRequest);

function InitializeRequest(sender, args) {


    $get(args._postBackElement.id).disabled = true;
}

function EndRequest(sender, args) {


    $get(sender._postBackSettings.sourceElement.id).disabled = false;
}