err = 0;
errc = ['OK'];
errc[1] = 'Please verify the zip code (5 or 9 digits).';
errc[2] = 'Please enter the telephone number, including area code.';
errc[3] = 'Please check the expiration date: four digits, '
+ 'e.g., 0709 is the correct date for July, 2009.';
errc[4] = 'This card is not working; can you check the card number again?';
errc[5] = 'Please do not leave this field blank.';
errc[6] = 'Please fill in the email address.';
errc[7] = 'Please check the expiration date: apparently it is expired.';
errc[8] = 'Please check the expiration date: it is not valid.';
errc[9] = 'Please complete the entry.';
errc[10] = 'Please enter a numerical value (may include an exponent e+N).';
errc[11] = 'Please enter a complete URL.';


function nwts(s) { // no white space
	return s.replace(/\s+/g, '');
}

function trimwts(s) { // trim white space
	return s.replace(/^\s+|\s+$/g, '');
}

function number(s) { // any number, including exponent
	s = nwts(s)-0;
	err = isNaN(s) ? 10 : 0;
	return [err ? 0 : s];
}

function zip(s) { // zip code
	var a = nwts(s).match(/\d{5}(-?\d{4}){0,1}/g);
	err = a != null && a.length ? 0 : 1;
	return a;
}

function tel(s) { // telephone, with area code + opt prefixes
	var a = s.replace(/\D+/g, '-');
	a = a.match(/(\d+-?)*(\d{3}-?){2}\d{4}/g);
	err = a != null && a.length ? 0 : 2;
	return a;
}

/* this code is copied from
http://www.codelib.net/home/jkm/checksum.js */
function checksum(s) { // thanks to daniel_amor@hp.com for AMEX specs
	var p=0, e=8, t=0, c=[], r=0, l=0, i;

	if (s.length != 16) {
		t = 1;
		e = s.length == 13 && 6 || s.length == 15 && 7;
	}
	
	for (i=p; i<e; i++)
		r += (c[i] = s.charAt(i*2+t) * 2) > 9
	? Math.floor(c[i]/10 + c[i]%10) : c[i];

	for (i=p; i<e+t; i++) l += s.charAt(i*2+1-t)-0;
	l += r;
	return e && l%10 == 0;
}

function cardno(s) {
	s = s.replace(/\D+/g, '');
	err = checksum(s) ? 0 : 4;
	return [s];
}

function text(s) {
	s = trimwts(s);
	err = s.length ? 0 : 5;
	return [s];
}

function words(s) {
	s = trimwts(s);
	err = /\s/.test(s) ? 0 : 9;
	return [s];
}

function email(s) {
	a = s.match(/\S+@([-\w]+\.)+\w+/g);
	err = a != null && a.length ? 0 : 6;
	return a;
}

function url(s) {
	a = s.match(/\w{2,}:\/{2}([-\w]+\.)+\w+\S*/g);
	err = a != null && a.length ? 0 : 11;
	return a;
}

function expires(s) {
	s = nwts(s);
	var m = new Date()
	var m_year = m.getFullYear()%100, m_month = m.getMonth();

	if (s.length != 4 || isNaN(s))
		err = 3;
	else {
		s_month = s.substring(0,2)-0;
		s_year = s.substring(2, 4)-0;

		if (m_year > 70 && s_year < 30) s_year += 100;
		/* "Let your great grandson worry about that." */

		if (s_year < m_year || s_year > m_year + 6) err = 8;
		else if (s_year == m_year && !(s_month > m_month)) err = 7;
		else err = 0;
	}
	return [s];
}

function valid(element, check) {
	if (element.type == 'text' || element.type == 'textarea') {
		return check(element.value);
	} else return check(element);
}

present_element = null, present_error = null;
function validate(form, list) {
	for (i=0; i<form.elements.length; i++) {
		var element = form.elements[i];
		var n = element.name, out;
		if (list[n] && list[n].verify) {
			out = valid(element, list[n].verify);
			if (err && (list[n].force || present_element != element || present_error != err)) {
				present_error = err;
				present_element = element;
				alert(list[n].message || errc[err]);
				element.focus();
				return false;
			} else if (!err && list[n].filter)
				element.value = out.join(', ');
		}
	}
	
	// sal's hack
	var disclaimer = document.getElementById('disclaimer');

	// do check to see if check box was hit
	if ( disclaimer.checked != true ) {
		alert("Please check the box indicating you have read the recipe submital disclaimer located above the 'Add My Recipe' button.");
		return false;
	}
	
	var peopleImg = document.getElementById('peoplePhoto');
	
	if ( peopleImg.value != '' ) {
		var info = document.getElementById('personal_info');
		
		if ( info.value == '' ) {
			alert('You have to enter some personal information about yourself if you want your picture to appear.');
			return false;
		}
	}

	return true;
}