Something

function swap(targetId) {
	if (document.getElementById) {
		var target = document.getElementById(targetId);
	           
		var child = document.getElementById(targetId);
		var parent = child.parentNode;
	           
		var divList = parent.getElementsByTagName("div");
	         
		if (target.style.display == "none") {
			target.style.display = "block";
		}
		else {
			target.style.display = "none";
		}
	}
}