function correctHeight() {
		var heightAdd = document.getElementById("introid").offsetHeight;
		
		
		
		if (self.innerHeight) {
			
			x = self.innerWidth;
			y = self.innerHeight;
			
			} else if (document.documentElement && document.documentElement.clientHeight) {
				x = document.documentElement.clientWidth;
				y = document.documentElement.clientHeight;
				
			} else if (document.body) {
				x = document.body.clientWidth;
				y = document.body.clientHeight;
				
			}
			
		
			var height_pre = document.getElementById('mainid').offsetHeight;
			
			if(height_pre <= y) {
				document.getElementById("introid").style.height =  y - 280+ 'px';
			}
	}
	
	var root = window.addEventListener || window.attachEvent ? window : document.addEventListener ? document : null;

	if (root){
		if (root.addEventListener) root.addEventListener("load", correctHeight, false);
		else if (root.attachEvent) root.attachEvent("onload", correctHeight);
	}
	
	window.onresize = correctHeight;