function checkForm() {
	if ( document.warrantyForm.name.value == '' ) {
		alert("Please enter your name.");
		return false;
	}

	if ( document.warrantyForm.address.value == '' ) {
		alert("Please enter your address.");
		return false;
	}

	if ( document.warrantyForm.city.value == '' ) {
		alert("Please enter your city.");
		return false;
	}

	if ( document.warrantyForm.postalCode.value == '' ) {
		alert("Please enter your postal code.");
		return false;
	}

	if ( document.warrantyForm.phone.value == '' ) {
		alert("Please enter your telephone number.");
		return false;
	}

	if ( document.warrantyForm.email.value == '' ) {
		alert("Please enter your e-mail address.");
		return false;
	}

	if ( document.warrantyForm.serialNumber.value == '' ) {
		alert("Please enter your printer's serial number.");
		return false;
	}

}