body
{
	background-color:#000000;
}

div.bt1
{
	background-image:url(images/arriere_plan.jpg);
	height: 78px;
	width:23%;
	text-align:center;
	top:0px;
	margin-left:1%;
}

div.bt2
{
	background-image:url(images/arriere_plan.jpg);
	height: 78px;
	width:23%;
	text-align:center;
	margin-top:-78px;
	margin-left:26%;
}

div.bt3
{
	background-image:url(images/arriere_plan.jpg);
	height: 78px;
	width:23%;
	text-align:center;
	margin-top:-78px;
	margin-left:51%;
}

div.bt4
{
	background-image:url(images/arriere_plan.jpg);
	height: 78px;
	width:23%;
	text-align:center;
	margin-top:-78px;
	margin-left:76%;
}

img
{
	border:0;
}