function checkrequired(ADDUser) {
if (ADDUser.name.value=="") {
    alert("Please input your name.");
    ADDUser.name.focus();
    return (false);
}

if (ADDUser.tel.value=="") {
    alert("Please input your telephone number.");
    ADDUser.tel.focus();
    return (false);
}

if (ADDUser.email.value=="") {
    alert("Please input your e-mail address.");
    ADDUser.email.focus();
    return (false);
}

if (ADDUser.email.value.indexOf("'",0) >= 0 || ADDUser.email.value.indexOf(" ",0) >= 0) {
    alert("e-mail address style error.")
    ADDUser.email.focus()
    return false
}

if (ADDUser.email.value.indexOf("@",0) < 0 || ADDUser.email.value.indexOf(".",0) < 0) {
    alert("e-mail address style error.")
    ADDUser.email.focus()
    return false
}

if (ADDUser.message.value=="") {
    alert("Please input your message.");
    ADDUser.message.focus();
    return (false);
}

return (true);
}