var iViewPortHeight;

// all except Explorer
if (self.innerHeight) {
	iViewPortHeight = self.innerHeight;
}
// Explorer 6 Strict Mode
else if (document.documentElement && document.documentElement.clientHeight) {
	iViewPortHeight = document.documentElement.clientHeight;
}
// other Explorers
else if (document.body) {
	iViewPortHeight = document.body.clientHeight;
}

var bIsIE = (document.all)
	? true
	: false
;

window.onload = function() {
	if (bIsIE) {
		/* header: 270, footer: 30 */
		var iNavHeight = iMainHeight = iViewPortHeight - 270 - 30;
		document.getElementById("navigation").style.height = iNavHeight + "px";
		document.getElementById("main").style.height = iNavHeight + "px";
	}
}