function getXPopup(width){

	var x = ( screen.width - width ) / 2
	return x
}
function getYPopup(height){
	var y =( screen.height - height ) / 2.3
	
	return y
}
function showMenu( id ){
	document.getElementById(id).style.visibility = 'visible'		
}
function hideMenu( id ){
	document.getElementById(id).style.visibility = 'hidden'
}