if (screen.height<=800 && screen.width<=994)
{
document.write("<style>.conteneur{position:absolute;left: 0px; top: 0px;width: 1024px;height: 752px;}</style>");
}
else if (screen.height<=800 && screen.width>994)
{
document.write("<style>.conteneur{position:absolute;left: 50%; top: 0px;width: 1024px;height: 752px; margin-left: -512px;}</style>");
}
else if (screen.height>800 && screen.width<=994)
{
document.write("<style>.conteneur{position:absolute;left: 0px; top: 50%; width: 1024px;height: 752px; margin-top: -376px;}</style>");
}
else if (screen.height>800 && screen.width>994)
{
document.write("<style>.conteneur{position:absolute;left: 50%; top: 50%;width: 1024px;height: 752px;margin-top: -376px; /* moitié de la hauteur */margin-left: -512px; /* moitié de la largeur */}</style>");
}