function openTab(id) {
	closeAllTabs();
	var element = document.getElementById(id+"_tab");
	element.className = "opentab";
}

function closeAllTabs() {
	var element = document.getElementById("bigTabs");
	var subdivs = element.getElementsByTagName("div");
	for (var i=0;i<subdivs.length;i++) {
		if(subdivs[i].className == "opentab") {
			subdivs[i].className = "closedtab";
		}
	}
}