Can't comment JavaScript in Visual Studio

In Visual Studio 2008, a JavaScript 开发者_如何学运维function, I comment the line，. It's a usercontrol, and I get it in JavaScript. I want to comment the line, but it didn't work ( whether I add // or /* */, it doesn't work).

var user = document.getElementById('<%=UCSeletUser.ClientID %>'); 

Your problem is that your JavaScript comments are just text like anything else to the ASPX processor. Anything not inside of the script markers is treated as a string literal -- it doesn't know or care that it's a JavaScript comment. It goes through the page looking for script sections (<% %>) and doing whatever is inside them, regardless of the surrounding text. (Things work slightly differently for databinding code <%# %>, but that's not relevant to your question.)

If you don't want that script block to run, you need to either take it out, or comment it out with server-side comments:

C#:    //var user = document.getElementById('<%//=UCSeletUser.ClientID %>');
VB:    //var user = document.getElementById('<%'=UCSeletUser.ClientID %>');

If you have multiple script sections and you don't want to comment out each one where they may be related, you can use a script section to comment out all of it:

<%--
    var user = document.getElementById('<%=UCSeletUser.ClientID %>');
    var someOtherVal = document.getElementById('<%=someOtherVal.ClientID %>');
    var anotherVal = document.getElementById('<%=anotherVal.ClientID %>');
--%>

Of course, you can highlight multiple lines and use the Visual Studio command ctrl-K, ctrl-C to comment the lines out. Use ctrl-K, ctrl-U to uncomment.