function initHeight(){
	var _wrapper = document.getElementById("wrapper");
	var _main = document.getElementById("main");
	var _header = document.getElementById("header");
	var _footer = document.getElementById("footer");
	if (_main && _header && _footer){
		if(_wrapper.offsetHeight < document.documentElement.clientHeight){
			_main.style.height = document.documentElement.clientHeight -_header.offsetHeight -_footer.offsetHeight - 44 + "px";
		}
	}
	
}
if (window.addEventListener)
	window.addEventListener("load", initHeight, false);
else if (window.attachEvent && !window.opera)
	window.attachEvent("onload", initHeight);