function Divshowhide(x,y){
	var s,r;
	var x,y;
	var id;
	var itm = false;
	if(x==1){
		id='alunos';
		ob='alunosbt';
	}else if(x==2){
		id='cursos';
		ob='cursosbt';
	}else{
		return false;
	}
	if(document.getElementById){
		itm = document.getElementById(id);
		obj = document.getElementById(ob);
	}else if(document.all){
		itm = document.all[id];
		obj= document.all[ob];
	}else if(document.layers){
		itm = document.layers[id];
		obj= document.layers[ob];
		return itm;
		return obj;
	}
	
	if(y==1){
		itm.style.zIndex=3;
		itm.style.visibility='visible';
	}else{
		itm.style.zIndex=1;
		itm.style.visibility='hidden';
	}
	var topValue= 0,leftValue= 0;
	while(obj){
		leftValue+= obj.offsetLeft;
		topValue+= obj.offsetTop;
		obj= obj.offsetParent;
	}
	s = topValue + 25;
	r = leftValue;
	itm.style.top=s+"px";
	itm.style.left=r+"px";
}