problem with div height

hi guys,



im making a website using divs. im not exactly crash hot with
divs and coding but so far the majority of the site seems to work!



there is a div called contentHolder that i want to cover
between my header image and footer div. when there is no scrolling
needed on the page it works perfectly but when the page needs to be
scrolled, the div just cuts off as soon as the page is scrolled.



the 'content' div is placed inside the contentHolder div and
i want that to push contentHolder down if needed.



you can view the test site at www.spindriftmedia.com/2007 -
if you check out a page that needs scrolling like portfolio
hopefully youll see what i mean.



the code im using in my css for these particular divs are:



#contentHolder {

position:absolute;

width:770px;

top: 240px;

left: 0px;

bottom:0px;

background-color:#FFFFFF;

}

#content {

position:absolute;

width:562px;

left: 20px;

top: 20px;

padding-bottom:20px;

}



any help would be greatly appreciated. hope ive explained
this ok!



thank you very much.



all the best,



mark