This is possible. See Passing JavaScript arguments via the src attribute. The punchline is that since scripts in HTML (not XHTML) are executed as loaded, this will allow a script to find itself as it is always the last script in the page when it’s triggered–
var scripts = document.getElementsByTagName('script');
var index = scripts.length - 1;
var myScript = scripts[index];
// myScript now contains our script object
var queryString = myScript.src.replace(/^[^\?]+\??/,'');
Then you just apply the query string parsing.