IE8 browers will default to IE7 document mode if the headers are not enforced.
Add the DOC type before the html tag
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
and the meta tag in the header section
<meta http-equiv="x-ua-compatible" content="IE=8" >
IT will make life a lot easier but newer browsers will also view in IE8.