function montre(id) {
	  if (document.getElementById) {
		  document.getElementById(id).style.visibility="visible";
		} else if (document.all) {
		  document.all[id].style.visibility="visible";
		} else if (document.layers) {
		  document.layers[id].visibility="visible";
		} } 
		
    function cache(id) {
	  if (document.getElementById) {
		  document.getElementById(id).style.visibility="hidden";
		} else if (document.all) {
		  document.all[id].style.visibility="hidden";
		} else if (document.layers) {
		  document.layers[id].visibility="hidden";
		} }
function montre_img(id) {
	  if (document.getElementById) {
	      cache('img_1');
	      cache('img_2');
	      cache('img_3');
	      cache('img_4');
	      cache('img_5');
	      cache('img_6');
	      cache('img_7');
	      cache('img_8');
	      cache('img_9');
	      cache('img_10');
		  document.getElementById(id).style.visibility="visible";
		} else if (document.all) {
		  document.all[id].style.visibility="visible";
		} else if (document.layers) {
		  document.layers[id].visibility="visible";
		} }