Personalizing the header...help

Hi all,

I have read through every single post that even comes close to this topic, but I am sure I have missed this somewhere since so many of you seem to have figured this out. Kindly help this poor girl anyway since I have to get this site ready for my boss.

I need to change the header in the textures template of webstyle. I figured out that I had to change it in DW, so that is what I am doing now. I played with the code until I removed the original header and now I am making my own graphic for it.

My question is how do I make sure that the header will work with the webstyle css? I plan to insert my header at this line:

<div id="header">
<div align="center">
</div>
<div align="center"><img src="../newbellavita%20site/logoexpanded.jpg" width="357" height="150"> </div>
<div id="logo"></div>

Will this cause a problem? Thanks for any help, Christy