How do I pass a server control's actual client Id to a javascript function?

Question

I have the following textbox server control in my web page:

Answer 1

Put the <%= txtZip.ClientId %> between single quotes, to be like this:

'<%= txtZip.ClientId %>'

Update

Please check this article: http://www.jagregory.com/writings/how-to-use-clientids-in-javascript-without-the-ugliness/

Also I like this answer