You can't randomly stick JavaScript anywhere you like in HTML.
When you are in the middle of an HTML start tag you can either:
- End the tag with
>
- Write an attribute
JavaScript does not belong there.
If you want to generate an HTML attribute value dynamically when the element is created, then you must create the entire element with JavaScript.
e.g.
<script>
var s = document.createElement("script");
s.src = "myfile.js"?+Date.now();
document.head.appendChild(s);
</script>
… but you'd probably be better of solving this problem by properly configuring your HTTP headers for the script instead.