function set_server(f) {
    srv = new Array(
      'libo', 'graff', 'jane', 'miro', 'ela', 'hivequeen', 
      'alai', 'mazer', 'grego', 'arkanian', 'bean'
    )
    idx = f.user.value.substr(1,2).replace(/^0/, '')
    idx = parseInt(idx) - 1
    if (isNaN(idx)) {
        return false
    } else if (idx < 0 || idx > srv.length - 1) {
         alert('Nombre de usuario incorrecto')
         return false
    } else {
        if ((idx == 0) && f.user.value.match(/^s01[0-6]/)) {
            idx = 10
        }
        if ((idx == 1) && f.user.value.match(/^s02[01]/)) {
            idx = 10
        }
        if ((idx == 4) && f.user.value.match(/^s05[0-2]/)) {
            idx = 10
        }
        if  ((idx == 4) && f.user.value.match(/^s05[3-7]/)) {
            idx = 5
        }
        if  ((idx == 4) && f.user.value.match(/^s05[8-9a-f]/)) {
            idx = 2
        }
        if ((idx == 2) && f.user.value.match(/^s03[0]/)) {
            idx = 8
        }
        f.action = 'https://' + srv[idx] + '.h3m.com:2083/login/'
    }
}