function bougeVignette(theClass) {
	//Populate the array with all the page tags
  var allPageTags=document.getElementsByTagName("*");
  //Cycle through the tags using a for loop
  for (i=0; i<allPageTags.length; i++) {
  //Pick out the tags with our class name
  	if (allPageTags[i].className==theClass) {
  		//Manipulate this in whatever way you want
    	allPageTags[i].style.zIndex='0';
    	allPageTags[i].style.top='50px';
  	}
  }
	document.getElementById("ecran").innerHTML = texteDefault;
}

function top(element,texte) {
	bougeVignette("vignette");
  element.style.zIndex = '10';
  element.style.top = '70px';
  document.getElementById("ecran").innerHTML = texte;
}