function rollof(){
  	cible=document.getElementById("imgRoll");
  	cible.onmouseover=function(){cible.setAttribute("src","images/img-contact2.gif");}
    cible.onfocus=function(){cible.setAttribute("src","images/img-contact2.gif");}
  	cible.onmouseout=function(){cible.setAttribute("src","images/img-contact.gif");}
    cible.onblur=function(){cible.setAttribute("src","images/img-contact.gif");}    
  }