html code:
Jquery Code:
$(\'[id$=b
It wouldn't work because the generated HTML id is different than the ASP.NET id.
So btnTest will be rendered as another Id.
A quick dirty way is to to run the page, view the HTML source and locate the button's generated Id and pass it as an arugment in the jQuery function.
A better way is to generate the jQuery function through code behind:
Literal1.Text = "$('[id$=" + btnTest.ClientId + "]').click(function(
{$(this).attr('disabled', 'disabled');});";
Edit: Also I couldn't help but realize that your OnClick attribute should point to btnTest_Click and not btn_Click