function setVisible(obj, bool){
	if(typeof obj == "string")
		obj = document.getElementById(obj);
	if(bool == false){
		if(obj.style.display != 'none');
			obj.style.display = 'none';
		}
	else { 
		if(obj.style.display != 'block');
		obj.style.display = 'block';
	}
}