var os = "win";

if (navigator.platform.indexOf("Win32") != -1)
	os = "win";
else if (navigator.platform.indexOf("Linux") != -1)
	os = "linux";
else if (navigator.userAgent.indexOf("Mac OS X") != -1)
	os = "mac";
else if (navigator.userAgent.indexOf("MSIE 5.2") != -1)
	os = "mac";
else if (navigator.platform.indexOf("Mac") != -1)
	os = "mac";
	
document.getElementById(os).style.display = "block";

function showInstructions(newos, oldos) {
	$(oldos).style.display = "none";
	$(newos).style.display = "block";
}

function $(el) {
	if (document.getElementById) {
		return document.getElementById(el);
	}
}