304276 Centering Page

I used a program called bluevoda site builder which is a click and drag site builder. The site when finished looks perfectly centered for my computer, which is a laptop; but, when I go to a wide screen then the whole site isn't centered at all. I've noticed that it looks centered with laptops, but not with desktop monitors, especially wide screens. I had a friend that is more familiar take a look at the code to see if there was a quick fix, but he said there is CSS code so it'll be hard. I need help getting everything centered for ALL monitor screens! Also I just changed the resolution so that it can look centered to most, but now the resolution is too large on the width. It's 1240 and i want to change it back to 1024, which is super easy, but I just mainly need to center all the middle part of the page for all monitors at all times. Meaning that whenever the resolution on the screen changes from someone minimizing and maximizing the browser it will still stay centered.