function checkf(contact) {

if (contact.contactname.value == "") {
alert("Please enter your name.");
contact.contactname.focus();
return false;
}
if (contact.email.value == "") {
alert("Please enter a valid email address.");
contact.email.focus();
return false;
}
if (contact.subject.value == "") {
alert("Please select the type of service you require.");
contact.subject.focus();
return false;
}

}