Fix template to make it adjustable

I have a website (asp.NET) that uses two templates [login to view URL] and footer.html. It was intended to fit a standard screen size but now site visitors need to scroll horizontally to see the whole page. I need to fix this template so? visitors can see the whole page either if? they have the left window of your browser enabled. This may be a very simple thing to start, but we will need a new set of templates, several schemes (skins),? designed in the very near future (maybe after finishing this task).