I am building a site with Mediawiki which is a built web tool for wiki sites (like wikipedia). so anyway, i tried to change the generak apperance and worked my way and changed the main skin and the "main.css" of this skin. i never learned css but i try things and changed until i got the apperance i wanted but now when i check the site with firefox i can't see it well and the right menu bar is not clickable at all. i came to conculsion that the problem is with the differences between the web browsers. i dont really know what i should do with it, what changes i need to make with every web browser fix css file. My site is seen normally with IE7. Thank you.