function validate(f)
{
    if (f.name.value == "")
    {
        alert("Please tell us your name");
        f.name.focus();
        return false;
    }

    if (f.email.value == "")
    {
        alert("Please tell us your email address so we may respond to your inquiry");
        f.email.focus();
        return false;
    }

    if (f.email.value.indexOf(".") == -1)
    {
        alert("Please enter a valid email address (you have not entered a full stop anywhere)");
        f.email.focus();
        return false;
    }

    if (f.email.value.indexOf("@") == -1)
    {
        alert("Please enter a valid email address (you have not entered an @ sign)");
        f.email.focus();
        return false;
    }

    if (f.subject.value == "")
    {
        alert("Please tell us the subject of your inquiry");
        f.subject.focus();
        return false;
    }

    if (f.message.value == "")
    {
        alert("Please provide details about your inquiry");
        f.message.focus();
        return false;
    }

    // All fields are OK

    return true;
}