Passing parameters to JavaScript files

Often I will have a JavaScript file that I want to use which requires certain variables be defined in my web page.

So the code is something like this:

<script type="text/javascript" src="https://stackoverflow.com/questions/2190801/file.js"></script>
<script type="text/javascript">
   var obj1 = "somevalue";
</script>

But what I want to do is:

<script type="text/javascript" 
     src="https://stackoverflow.com/questions/2190801/file.js?obj1=somevalue&obj2=someothervalue"></script>

I tried different methods and the best one yet is to parse the query string like this:

var scriptSrc = document.getElementById("myscript").src.toLowerCase();

And then search for my values.

I wonder if there is another way to do this without building a function to parse my string.

Do you all know other methods?