function randbg() {
	var backgr1='rand1';
	var backgr2='rand2';
	var backgr3='rand3';
	
	var cur=Math.round(6*Math.random());
	if (cur<=1)
		backgr = backgr1;
	else if (cur<=4)
		backgr = backgr2;
	else
		backgr = backgr3;
	
	document.getElementById('leftLinks').className = backgr;
}