I built a website RNL Services LLC

Looks like crap when viewed in 600 x 800 browsers. The content collapses. If you are on a higher resolution browser you can see what I am talking about by resizing your browser.

I would like to emulate what happens at the following website Merchants Bonding Company

The following is my css

Code:
html, body, #wrapper {
    height:100%;
    margin: 0;
    padding: 0;
    border: none;
    text-align: center;
}
#wrapper {
   margin: 0 auto;
   text-align: left;
   vertical-align: middle;
   width: 400px;
}
#page_home {
	height: 635px;
	width: 974px;
	margin-top: -8px;
	margin-right: auto;
	margin-left: auto;
}
Go to RNL Services LLC to see the source.

Thanks in advance for any help