function OuvrirExplicationFenetre()
{
var largeur = screen.width ; 
if (largeur >= 1024)
	{
	window.open('','explain','width=800,height=600,scrollbars=1,menubar=0,toolbar=0,resizable=1');
	}
if (largeur < 1024)
    {
	window.open('','explain','width=500,height=300,scrollbars=1,menubar=0,toolbar=0,resizable=1');
	}

}