function pre_load_imgs()
{ (new Image()).src = "images/entrer_nouveau_over.png";
  (new Image()).src = "images/entrer_ancien_over.png";
}

function roll_over_ancien()
{ if(document.getElementById)
  { if(document.getElementById("img_old"))
    { document.getElementById("img_old").onmouseover = function()
	  { document.getElementById("enter_old").style.backgroundImage = "url(images/entrer_ancien_over.png)";
	  }
      document.getElementById("img_old").onmouseout  = function()
	  { document.getElementById("enter_old").style.backgroundImage = "url(images/entrer_ancien.png)";
	  }
    }
  }
}

function roll_over_nouveau()
{ if(document.getElementById)
  { if(document.getElementById("img_new"))
    { document.getElementById("img_new").onmouseover = function()
	  { document.getElementById("enter_new").style.backgroundImage = "url(images/entrer_nouveau_over.png)";
	  }
      document.getElementById("img_new").onmouseout  = function()
	  { document.getElementById("enter_new").style.backgroundImage = "url(images/entrer_nouveau.png)";
	  }
    }
  }
}

function roll_over_ancien_button()
{ if(document.getElementById)
  { if(document.getElementById("enter_old"))
    { document.getElementById("enter_old").onmouseover = function()
	  { document.getElementById("enter_old").style.backgroundImage = "url(images/entrer_ancien_over.png)";
	  }
      document.getElementById("enter_old").onmouseout  = function()
	  { document.getElementById("enter_old").style.backgroundImage = "url(images/entrer_ancien.png)";
	  }
    }
  }
}

function roll_over_nouveau_button()
{ if(document.getElementById)
  { if(document.getElementById("enter_new"))
    { document.getElementById("enter_new").onmouseover = function()
	  { document.getElementById("enter_new").style.backgroundImage = "url(images/entrer_nouveau_over.png)";
	  }
      document.getElementById("enter_new").onmouseout  = function()
	  { document.getElementById("enter_new").style.backgroundImage = "url(images/entrer_nouveau.png)";
	  }
    }
  }
}

function addLoadEvent(func)
{ var oldonload = window.onload;
  if(typeof window.onload != 'function') window.onload = func;
  else
  { window.onload = function()
    { if(oldonload) oldonload();
      func();
    }
  }
}

addLoadEvent(roll_over_ancien);
addLoadEvent(roll_over_nouveau);
addLoadEvent(roll_over_ancien_button);
addLoadEvent(roll_over_nouveau_button);
addLoadEvent(pre_load_imgs);