Now, with your help i've done the layout without many problems.
But, now i'm trying another thing (to add some details to the web).
I'm trying to add a drop shadow on the menu and content boxes.
I have done it with the original images from the site (with white background), but i decided to try it with transparent .png to keep the lines background i used.
I decided to use .png instead .gif because it looks greater with transparences.
With this decisions, i've two problems.
First, the IE compatibility with .png alpha channels. I've tried some fixes with no luck.
And the second problem is the transparency itself. In the corners the transparency allows to see the wrap1 image.
a picture to show it:
thanks for your help