function pres2()
{
chemin='livre/livre.aspx'

window.open(chemin,'','dependent=yes,width=550,toolbar=no,height=600,scrollbars=yes')
}

function pres3()
{
chemin='mail.aspx'

window.open(chemin,'','dependent=yes,width=550,toolbar=no,height=400,scrollbars=yes')
}
function pres4()
{
chemin='lien.html'

window.open(chemin,'','dependent=yes,width=550,toolbar=no,height=600,scrollbars=yes')
}