function empty_field(field, msg)

{

	var not_empty_rx = /\S/;

	var field_str = field.value.toString();



	if (!field_str.match(not_empty_rx))

	{

		fix_element(field, msg);

		return true;

	}



	if (field.value == "")

	{

		fix_element(field, msg);

		return true;

	}

	else

	{

		return false;

	}

}



function fix_element(element, msg)

{

	alert(msg);

	element.focus();

}



function trim_string(str)

{

	var s_input = new String(str);

	var i_start, i_end;

	var s_trimmed;

	var c_char;



	i_end = s_input.length - 1;

	i_start = 0;

	

	c_char = s_input.charAt(i_start);

	while ((i_start < i_end) && ((c_char == "\n") || (c_char == "\r") || (c_char == "\t") || (c_char == " ")))

	{

		i_start++;

		c_char = s_input.charAt(i_start);

	}



	c_char = s_input.charAt(i_end);

	while ((i_end >= 0) && ((c_char == "\n") || (c_char == "\r") || (c_char == "\t") || (c_char == " ")))

	{

		i_end--;

		c_char = s_input.charAt(i_end);

	}



	s_trimmed = (i_start <= i_end ? s_input.substring(i_start,i_end+1) : '');

	return s_trimmed;

}



function check_email(o_email)

{

	var s_trimmed_email = new String(trim_string(o_email.value));

	

	var rx_email = /^(.+)@(.+)$/;

	var rx_special_chars = "\\(\\)<>@,$/;:\\\\\\\"\\.\\[\\]";

	var rx_valid_chars = "\[^\\s" + rx_special_chars + "\]";

	var rx_quoted_user = "(\"[^\"]*\")";

	var rx_ip_domain = /^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;

	var rx_atom = rx_valid_chars + '+';

	var rx_word = "(" + rx_atom + "|" + rx_quoted_user + ")";

	var rx_user = new RegExp("^" + rx_word + "(\\." + rx_word + ")*$");

	var rx_domain = new RegExp("^" + rx_atom + "(\\." + rx_atom +")*$");



	var a_match = s_trimmed_email.match(rx_email);



	if (a_match == null)

	{

		fix_element(o_email, "E-mail address seems to be incorrect (check @ and .'s)");

		return false;

	}



	var s_user = a_match[1];

	var s_domain = a_match[2];



	if (s_user.match(rx_user) == null)

	{

		fix_element(o_email, "Your e-mail username doesn't seem to be valid.");

		return false;

	}



	var a_IP = s_domain.match(rx_ip_domain);

	if (a_IP != null)

	{

		for (var i =1; i <= 4; i++)

		{

			if (a_IP[i] > 255)

			{

				fix_element(o_email, "Your e-mail Destination IP address is invalid!");

				return false;

			}

		}

		return true;

	}



	var a_domain = s_domain.match(rx_domain)

	if (a_domain == null)

	{

		fix_element(o_email, "The domain name in your e-mail address doesn't seem to be valid.");

		return false;

	}



	var rx_atoms = new RegExp(rx_atom,"g");

	var a_dom = s_domain.match(rx_atoms);

	var i_len = a_dom.length;

	if (a_dom[a_dom.length - 1].length < 2 || a_dom[a_dom.length - 1].length > 3)

	{

		fix_element(o_email, "The e-mail address must end in a three-letter domain, or two letter country.");

		return false;

	}



	if ( i_len < 2)

	{

		fix_element(o_email, "This e-mail address is missing a hostname!");

		return false;

	}



	o_email.value = s_trimmed_email;

	return true;

}



function default_selected(selbox)

{

	return !selbox.selectedIndex;

}



function validate(form)

{

	with (form)

	{

		name.value	= trim_string(name.value);

		email.value	= trim_string(email.value);

		address.value	= trim_string(address.value);

		city.value	= trim_string(city.value);

		phone.value	= trim_string(phone.value);

		work_areacode.value	= trim_string(work_areacode.value);

		work_phone.value	= trim_string(work_phone.value);

		zipcode.value	= trim_string(zipcode.value);

		model.value	= trim_string(model.value);

		color.value	= trim_string(color.value);

		vin.value	= trim_string(vin.value);

		

		if (empty_field(name, "Please enter your Full Name.")) { return false; }

		if (empty_field(email, "Please enter your E-mail Address.")) { return false; }

		if (empty_field(address, "Please enter your Address.")) { return false; }

		if (empty_field(city, "Please enter your City of residence.")) { return false; }

		if (default_selected(state)) { fix_element(state, "Please select your state of residence."); return false; }

		if (empty_field(zipcode, "Please enter your Zip Code.")) { return false; }

		if (empty_field(areacode, "Please enter a value for the Area code field.")) { return false; }

		if (empty_field(phone, "Please enter a value for the Phone field.")) { return false; }

		if (default_selected(howdidyouhearaboutus)) { fix_element(howdidyouhearaboutus, "Please choose an option for:\nHow did you hear about us?"); return false; }

		if (default_selected(make)) { fix_element(make, "Please specify a make for your vehicle."); return false; }

		if (empty_field(model, "Please specify a model for your vehicle.")) { return false; }

		if (default_selected(year)) { fix_element(year, "Please specify the year your vehicle was made."); return false; }

		if (empty_field(color, "You left the color field blank. Please specify the color of your vehicle.")) { return  false; }

		if (empty_field(vin, "You left the VIN field blank. It must appear on the receipt./n If you wish to write it in later on the receipt, type ?.")) { return  false; }

		if (default_selected(drivability)) { fix_element(drivability, "Please specify the drivability of your vehicle."); return false; }



		return check_email(email);

	}

}