// Checks for numbers greater than 0
function checkNumbers(e) {
ok = "1234567890";
for(i=0; i < e.length ;i++){
 if(ok.indexOf(e.charAt(i))<0){ 
  return (false); }} 
 if (document.images) {
  re = /^[1-9]+([0-9]+)?$/;
  if (e.match(re)) {
   return (-1); }
   }}

// Checks for valid US zip codes (zip or zip+4)
function checkZip(e) {
ok = "1234567890-";
for(i=0; i < e.length ;i++){
 if(ok.indexOf(e.charAt(i))<0){ 
  return (false); }} 
 if (document.images) {
  re = (/^\d{5}([\-]\d{4})?$/);
  if (e.match(re)) {
   return (-1); }
   }}

// Checks for valid us phone numbers
function checkPhone(e) {
ok = "1234567890-";
for(i=0; i < e.length ;i++){
 if(ok.indexOf(e.charAt(i))<0){ 
  return (false); }} 
 if (document.images) {
  re = (/^\d{3}\-\d{3}\-\d{4}$/);
  if (e.match(re)) {
   return (-1); }
   }}

// Checks for valid email accounts, structurally
function checkEmail(e) {
ok = "1234567890qwertyuiop[]asdfghjklzxcvbnm.@-_QWERTYUIOPASDFGHJKLZXCVBNM";
 for(i=0; i < e.length ;i++){
  if(ok.indexOf(e.charAt(i))<0){ 
   return (false); }} 
  if (document.images) {
   re = (/(@.*@)|(\.\.)|(^\.)|(^@)|(@$)|(\.$)|(@\.)/);
   re_two = (/^.+\@(\[?)[a-zA-Z0-9\-\.]+\.([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/);
   if (!e.match(re) && e.match(re_two)) {
    return (-1); }
	}}


function checkData() {
with (window.document.schreiber) {

	if (name.value == "") {
      alert ("Please provide your name.");
      name.focus ();
      return false; }

	if (addresstype.value == "Office Address")
	if (org.value == "") {
		alert ("You selected your office address, but didn't indicate your organization.  Please provide an organization name.");
		org.focus ();
		return false; }
	
	if (address.value == "") {
      alert ("Please provide your address.");
      address.focus ();
      return false; }
	  
	if (addresstype.value == "Select") {
      alert ("Please select an address type.");
      addresstype.focus ();
      return false; }

	if (city.value == "") {
      alert ("Please provide your city.");
      city.focus ();
      return false; }

	if (state.value == "") {
      alert ("Please provide your state.");
      state.focus ();
      return false; }

	if (!checkZip (zip.value)) {
	  alert ("Please provide your valid US zip code.");
	  zip.focus ();
	  return false; }
	  
	if (!checkPhone (phone.value)) {
      alert ("Please provide your valid phone number.");
      phone.focus ();
      return false; }
	  
	if (fax.value != "") // Not required if blank
	if (!checkPhone (fax.value)) {
      alert ("Please provide your valid fax number.");
      fax.focus ();
      return false; }

	if (email.value != "") // Not required if blank
	if (!checkEmail (email.value)) {
	  alert ("Please provide your valid e-mail address.");
	  email.focus ();
	  return false; }
	
	if ((conference[0].checked == true) || (conference[1].checked == true)) {
	if ((session1[0].checked == false) && (session1[1].checked == false) && (session1[2].checked == false)) {
		alert ("Please choose a morning session.");
		session1[0].focus ();
		return false; }
	if ((session2[0].checked == false) && (session2[1].checked == false) && (session2[2].checked == false)) {
		alert ("Please choose a early afternoon session.");
		session2[0].focus ();
		return false; }
	if ((session3[0].checked == false) && (session3[1].checked == false) && (session3[2].checked == false)) {
		alert ("Please choose a late afternoon session.");
		session3[0].focus ();
		return false; }
	}
	
	if (pay[3].checked == true)
	if (po.value == "") {
		alert ("Please provide a PO number.");
		po.focus ();
		return false; }
	  	
	}}