var alpha = 30;
var enter = true;
var mytime;
function BlocOver(){
	enter = true;
	SetAlpha();
}
function BlocOut(){
	enter = false;
	SetAlpha();
}
function SetAlpha(){
	window.clearTimeout(mytime);
	if (enter && alpha<100){
		alpha+=5;
		mytime = setTimeout("SetAlpha()",1);
	} else if (!enter && alpha>30) {
		alpha-=5;
		mytime = setTimeout("SetAlpha()",1);	
	}
	if (alpha==100){
		document.getElementById('titre-left').className = 'transparent30';
		document.getElementById('page-left').className = 'transparent30';
		document.getElementById('titre-right').className = 'transparent100';
		document.getElementById('page-right').className = 'transparent100';
	} else if (alpha==30){
		document.getElementById('titre-left').className = 'transparent100';
		document.getElementById('page-left').className = 'transparent100';
		document.getElementById('titre-right').className = 'transparent30';
		document.getElementById('page-right').className = 'transparent30';
	} else {
		document.getElementById('titre-left').className = 'transparent'+(130-alpha);
		document.getElementById('page-left').className = 'transparent'+(130-alpha);
		document.getElementById('titre-right').className = 'transparent'+alpha;
		document.getElementById('page-right').className = 'transparent'+alpha;		
	}

}