function fbCheckField() {
    var noerror = true;
    var element = document.getElementById('name');
    if (typeof(element)!='undefined' && element) {
        if (element.value.search(/[à-ÿÀ-ß\w]/)<0) {
            document.getElementById('name_error_field').className = 'err';
            noerror = false;
        }
        else {
            document.getElementById('name_error_field').className = 'ok';
            noerror = true;
        }
    }
    
    element = document.getElementById('message');
    if (typeof(element)!='undefined' && element) {
        if (element.value.search(/[à-ÿÀ-ß\w]/)<0) {
            document.getElementById('message_error_field').className = 'err';
            noerror = false;
        }
        else {
            document.getElementById('message_error_field').className = 'ok';
        }
    }
    
    element = document.getElementById('email');
    if (typeof(element)!='undefined' && element) {
        if (element.value!='' && !(/^[a-z][a-z0-9_\-\.]+@[a-z0-9_\-\.]+\.[a-z]{2,}$/.test(element.value))) {
            document.getElementById('email_error_field').className = 'err';
            noerror = false;
        }
        else {
            document.getElementById('email_error_field').className = 'ok';
        }
    }
    return noerror;
}