// JavaScript document

function validateForm()
{
    var f = document.feedbackForm;
    var e = f.elements;

    // Check every field has an entry
    for (i = 0; i < e.length; i++)
    {
        if (!(e[i].value))
        {
            alert("Please fill in the whole form before sending!");
            e[i].focus();
            return false;
        }
    }

    // Check e-mail address
    var email = f.email.value;
    var pos_at = email.indexOf('@');
    var pos_dot = email.lastIndexOf('.');
    if ((pos_at == -1)                      // No @
        || (pos_dot < pos_at)               // Last . before @
        || (pos_dot == email.length - 1))   // Last . at end
    {
        alert("Please enter a valid e-mail address");
        f.email.focus();
        return false;
    }

    // Otherwise all OK
    return true;
}