Embedding ASP.Net code in external javascript files

Question

I have a code like

var mySession = "<%= Session["MyID"] %>";
alert ( mySession );

and when I place this code in my aspx page inside a script tag, it works fine. But it doesn't work in an external js file. I am not able to figure out the problem.

Is there anything wrong in my code, or is it like this by default?

Answer 1

Server side scripts (<%= %>) are evaluated only inside aspx pages. External javascript are static files. To achieve what you are looking for you might need to declare a global js variable inside your aspx file:

var mySession = "<%= Session["MyID"] %>";

and use it in your external js:

alert(mySession);

Another option is to use AJAX. Set up a server side script which will return the required session value and call this script from the external js file.