//aligne verticalement un element par rapport à la page
function valigncenter(lmt)
{
	var page = document.documentElement;
	if(lmt && page)
	{
	    var containerHeight;
	    if (page.innerWidth)
	    {
            containerHeight = page.innerHeight;
		}
		else
		{
            containerHeight = page.clientHeight;
		}
	    var lmtHeight;
	    if (lmt.innerWidth)
	    {
            lmtHeight = lmt.innerHeight;
		}
		else
		{
            lmtHeight = lmt.offsetHeight;
		}
		var y = Math.ceil((containerHeight - lmtHeight) / 2);
		if(y < 0)
		{
			y = 0;
		}
		lmt.style.position = "relative";
		lmt.style.top = y + "px";
	}
	if (document.getElementById)
	{
		document.body.style.visibility = 'visible';
	}
}

function repositionne_layer(){
		$('container').style.position = 'absolute';
		$('container').style.paddingTop = '30px';
}