var nb_img = 4;
		tabDefil1 = new Array(nb_img);
		tabDefil1 [0] = "images/defil1_1.jpg";
		tabDefil1 [1] = "images/defil1_2.jpg";
		tabDefil1 [2] = "images/defil1_1.jpg";
		tabDefil1 [3] = "images/defil1_2.jpg";
		
		tabDefil2 = new Array(nb_img);
		tabDefil2 [0] = "images/defil2_1.jpg";
		tabDefil2 [1] = "images/defil2_2.jpg";
		tabDefil2 [2] = "images/defil2_1.jpg";
		tabDefil2 [3] = "images/defil2_2.jpg";
		
		tabDefil3 = new Array(nb_img);
		tabDefil3 [0] = "images/defil3_1.jpg";
		tabDefil3 [1] = "images/defil3_2.jpg";
		tabDefil3 [2] = "images/defil3_1.jpg";
		tabDefil3 [3] = "images/defil3_2.jpg";
		
		tabDefil4 = new Array(nb_img);
		tabDefil4 [0] = "images/defil4_1.jpg";
		tabDefil4 [1] = "images/defil4_2.jpg";
		tabDefil4 [2] = "images/defil4_1.jpg";
		tabDefil4 [3] = "images/defil4_2.jpg";
		
        var x = 0;
		var t = 1;
       	function startClock(){
			var i = x;
			eval("document.img"+t+".src=tabDefil"+t+"["+i+"]");
			t=t+1;
			
			setTimeout("startClock()", 1000)
			if(t==nb_img+1){
				t=1;
				x=x+1;
				if(x==nb_img) x=0
			}
        }