# Cannot modify an already defined ID selector?

**URL:** <https://forum.kirupa.com/t/cannot-modify-an-already-defined-id-selector/162567>\
**Category:** web dev\
**Created:** [September 14, 2005, 12:35pm UTC](https://forum.kirupa.com/t/cannot-modify-an-already-defined-id-selector/162567 "2005-09-14T12:35:52Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![IMJ](https://avatars.discourse-cdn.com/v4/letter/i/d2c977/32.png) [@IMJ](https://forum.kirupa.com/u/IMJ)\
**Post date:** [September 14, 2005, 12:35pm UTC](https://forum.kirupa.com/t/cannot-modify-an-already-defined-id-selector/162567/1 "2005-09-14T12:35:52Z")

</div>

I’m quite experienced with tableless layout pages, but I’m really getting lost now.

I made a site for my client some months ago, but now I have to modify the CSS due to some design changes. Unfortunately I can’t post some images of it, due to privacy issues, but the code basically looks like this:

```auto

<div id="menu">A bunch of menu items</div>
<div id="header"></div>
<div id="leftBar"></div>
<div id="wrapContent">
Content goes here
</div>
<div id="footer">Footer goes here</div>

```

Everything is positioned using float:left, except the menu, which is absolutely positioned on top of the header.

Since the menu has to be move up 100px, so I changed that. But guess what? I doesn’t change anything at all. I’ve tried with other ID selectors, changing background colors etc. Nothing happens.

It’s like I can’t modify anything or something. Has anyone had such an experience before? What can I do?

I’ve already emptied the cache and stuff, tested it on IE, FireFox and Opera, it’s all the same…

Hope someone can help and sorry for the long post!

Thanks in advance