var lastCnt = null;
var lastLnk = null;
var nothing = true;

function zobrazSkryj(who, what) {
	var oWhat = document.getElementById(what);
	if (lastCnt) {
		lastCnt.style.display = "none";
		lastLnk.style.color = "black";
	}
	if (lastCnt != oWhat || nothing) {
		oWhat.style.display = "block";
		who.style.color = "red";
		nothing = false;
	}
	else
		nothing = true;
	lastCnt = oWhat;
	lastLnk = who;
}