I looked for a long time how I could add JavaScript functions to an HTML document’s onLoad attribute.

Eventually I found this, something so obvious that I had considered trying it but foolishly didn’t try.

[code lang="JavaScript"]
var oldLoad = window.onload;
window.onload = function() {
oldLoad();
function2();
}
[/code]

I wanted to tell the user that they need JavaScript, but obviously only if they don’t already have it enabled.
The following is a very crude script which uses the very fact that JS is available to hide the requirement notice…

HTML:
[code lang="html"]

[/code]

JS:
[code lang="JavaScript"]
function removeElementById(eleId) {
eleId = document.getElementById(eleId);
if (eleId.parentNode && eleId.parentNode.removeChild) {
eleId.parentNode.removeChild(eleId);
}
}
removeElementById("jsRequiredDiv");
[/code]