Javascript question

How do you add some content in a specific place in Javascript at the user's bequest? I'm writing a sort of CSS designer with the idea that it shows the user what the style looks like by writing it to a file and then loading it (using PHP). The thing is I want it to actually be useful, so it needs to be able to have as many elements and properties as the user wants. I know that trick where you have an empty <div> and set its innerHTML member but that will leave me a set number, and I don't want to just stick billions and billions of <div> tags inside my code (its already messy enough).

tl; dr how do I dynamically instert code into a webpage at a set position but allowing an arbitrary number of insertions?

>>24
I tried that as well, it comes out blank.
>I just tried this:
>alert(document.getElementById("ee2e7a91").innerHTML);
>and it is blank.

I ran this:
alert(document.getElementById("ee2e7a91").innerHTML);
alert(document.getElementById("dda3fb44").innerHTML);
alert(document.getElementById("f15a1547").innerHTML);
and only the first one came out blank.

The second one is another div tag (I can't remember why, but it contains ee2e7a91 (I tried making ee2e7a91 the child of body instead but it didn't make a difference)) and the second is the <select></select> code I posted above.