function openWindow(url, windowName, width, height, params) { 
	// directories=yes/no, location=yes/no, menubar=yes/no, status=yes/no, scrollbars=yes/no, resizable=yes/no, toolbar=yes/no
	window.open(url, windowName, width=' + width + ', height=' + height + ', ' + params + ');
}
function hide(eltId){
	var e = document.getElementById(eltId);
	e.style.visibility = 'hidden';
	e.style.display = 'none';
}
function show(eltId){
	var e = document.getElementById(eltId);
	e.style.visibility = 'visible';
	e.style.display = 'block';
}
function showHide(eltId){
	var e = document.getElementById(eltId);
	if(e.style.visibility != 'visible'){
		show(eltId);
	}else{
		hide(eltId);
	}
}
function changeBgColor(eltId, color){
	var e = document.getElementById(eltId);
	e.style.backgroundColor = color;
}
function changeClassName(eltId, CssClass){
	var e = document.getElementById(eltId);
	e.className = cssClass;
}