function popItCentered(url, width, height)
{
	var left = Math.round(( screen.width - width ) / 2);
	var top = Math.round((screen.height - height ) / 2);
	
	popIt(url, top, left, width, height);
}
function openBook(url)
{
	var width = screen.width;
	var height = screen.height;
	var left =0; // Math.round(screen.width/ 2);
	var top = 0; //Math.round(screen.height/ 2);
	
	var winName = 'book'+Math.round(10000*Math.random());
	window.open(url, winName, 'top='+top+',left='+left+',width='+width+',height='+height+',resizable=yes,location=no,menubar=no,status=no,scrollbars=no,menubar=no');
}
//
function askBeforeRedirect(msg, url){
	var answer = confirm(msg);
	if ( answer ) window.location = url;	
}
function popupcentree(page,largeur,hauteur,options) 
{     
var top=(screen.height-hauteur)/2;    
var left=(screen.width-largeur)/2;    
window.open(page,"","top="+top+",left="+left+",width="+largeur+",height="+hauteur+","+options); 
}