Differences in different browsers - Duplicate commands

[Vag]

I have found a free Mambo template which I'm modifying for my web page.
I don't really know HTML or PHP or CSS, but as a programmer (Cobol, VB) I can understand some things.
What I don't understand is why some commands are two times in a row in there. Most times, there is a remark "Important" at the end of the first one.
Another problem is that the Firefox, Internet Explorer 6 and Internet Explorer 7 show the page differently!
I have tried very hard to tweak some details in the template (using Firefox), only to find out it doesn't work properly in IE 6 and 7 (it's even worse in 7). I'm sure that other browsers have problems as well.
What am I supposed to do in this case?

[eliasan]

Hi Vag,

The best advice I can give you is to study the following "Cascading Style Sheets, level 2 revision 1
CSS 2.1 Specification" guide from w3.org. It is in PDF format.

Trust me. It worths every second you invest on it.

That way you will understand firsthand, how CSS works, why you see differnces between browsers and how you can overcome them.

Perhaps, it is not the easy answer you were expecting, but it is better to learn how to fish, than expecting from others to feed you.