if (document.images)
{
 logo1 = new Image();
 logo2 = new Image();
 logo5 = new Image();
 logo6 = new Image(); 
 logo1.src = "/images/techno/menu_bt_guideinternet1.gif";
 logo2.src = "/images/techno/menu_bt_guideinternet2.gif";
 logo5.src = "/images/techno/menu_bt_dossiers1.gif";
 logo6.src = "/images/techno/menu_bt_dossiers2.gif"; 
}
function display(num)
{
  if (document.images)
  {
    if (num==1) document.guide.src    = logo1.src;
    if (num==2) document.guide.src    = logo2.src;
    if (num==5) document.dossiers.src = logo5.src;
    if (num==6) document.dossiers.src = logo6.src;
  }
}