function checkFormulaireInscription()
{
    var societe      = document.form.societe.value;
    var nbinterv     = document.form.nbinterv.value;
    var nom          = document.form.nom.value;
    var prenom       = document.form.prenom.value;
    var telephone    = document.form.telephone.value;
    var email        = document.form.email.value;
    var emailPattern = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;  
    ok = true;

    document.getElementById("thSociete").style.background   = "transparent";
    document.getElementById("thSociete").style.color        = "#000000";
    document.getElementById("thNbInterv").style.background   = "transparent";
    document.getElementById("thNbInterv").style.color        = "#000000";
    document.getElementById("thNom").style.background       = "transparent";
    document.getElementById("thNom").style.color            = "#000000";
    document.getElementById("thPrenom").style.background    = "transparent";
    document.getElementById("thPrenom").style.color         = "#000000";
    document.getElementById("thTelephone").style.background = "transparent";
    document.getElementById("thTelephone").style.color      = "#000000";
    document.getElementById("thEmail").style.background     = "transparent";
    document.getElementById("thEmail").style.color          = "#000000";

    if (! societe) {
        ok = false;
        document.getElementById("thSociete").style.color      = 'white';
        document.getElementById("thSociete").style.background = '#F36600';
    }

    if (! nbinterv) {
        ok = false;
        document.getElementById("thNbInterv").style.color      = 'white';
        document.getElementById("thNbInterv").style.background = '#F36600';
    }

    if (! nom) {
        ok = false;
        document.getElementById("thNom").style.color      = 'white';
        document.getElementById("thNom").style.background = '#F36600';
    }

    if (! prenom) {
        ok = false;
        document.getElementById("thPrenom").style.color      = 'white';
        document.getElementById("thPrenom").style.background = '#F36600';
    }

    if (! telephone) {
        ok = false;
        document.getElementById("thTelephone").style.color      = 'white';
        document.getElementById("thTelephone").style.background = '#F36600';
    }

    if (! emailPattern.test(email)) {
        ok = false;
        document.getElementById("thEmail").style.color      = 'white';
        document.getElementById("thEmail").style.background = '#F36600';
    }

    return ok;
}