// ----------------------------------------------------------------------
// Sweepstake Form Validation
// By: Zhongxi Shen
//
// Overstock.com
//
// This script is mostly based on Stephen Poley's code as explained at
// "http://www.xs4all.nl/~sbpoley/webmatters/formval.html".  The original
// revision note is kept below.
//
// OCT 11 2005: 
//     - Add validateDate, validateZipCode
//     - More flexible error message
//
// ----------------------------------------------------------------------

// ----------------------------------------------------------------------
// Javascript form validation routines.
// Author: Stephen Poley
//
// Simple routines to quickly pick up obvious typos.
// All validation routines return true if executed by an older browser:
// in this case validation must be left to the server.
//
// Update Aug 2004: have tested that IE 5.0 and IE 5.5 both support DOM model
// sufficiently well, so innerHTML option removed (redundant).
//
// Update Jun 2005: discovered that reason IE wasn't setting focus was
// due to an IE timing bug. Added 0.1 sec delay to fix.
//
// Update Oct 2005: minor tidy-up: unused parameter removed
// ----------------------------------------------------------------------

var nbsp = 160;    // non-breaking space char
var node_text = 3; // DOM text node-type
var emptyString = /^\s*$/;
var glb_vfld;      // retain vfld for timer thread

// -----------------------------------------
//                  trim
// Trim leading/trailing whitespace off string
// -----------------------------------------

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


// -----------------------------------------
//                  setfocus
// Delayed focus setting to get around IE bug
// -----------------------------------------

function setFocusDelayed()
{
  glb_vfld.focus()
}

function setfocus(vfld)
{
  // save vfld in global variable so value retained when routine exits
  glb_vfld = vfld;
  setTimeout( 'setFocusDelayed()', 100 );
}


// -----------------------------------------
//                  msg
// Display warn/error message in HTML element
// commonCheck routine must have previously been called
// -----------------------------------------

function msg(fld,     // id of element to display message in
             msgtype, // class to give element ("warn" or "error")
             message) // string to display
{
  // setting an empty string can give problems if later set to a 
  // non-empty string, so ensure a space present. (For Mozilla and Opera one could 
  // simply use a space, but IE demands something more, like a non-breaking space.)
  var dispmessage;
  if (emptyString.test(message)) { 
    dispmessage = String.fromCharCode(nbsp);    
  } else { 
    dispmessage = message;
  }
  
  var elem = document.getElementById(fld);
  elem.firstChild.nodeValue = dispmessage;  
  
  elem.className = msgtype;   // set the CSS class to adjust appearance of message
}

// -----------------------------------------
//            commonCheck
// Common code for all validation routines to:
// (a) check for older / less-equipped browsers
// (b) check if empty fields are required
// Returns true (validation passed), 
//         false (validation failed) or 
//         proceed (don't know yet)
// -----------------------------------------

var proceed = 2;  

function commonCheck    (vfld,  // element to be validated
                         ifld,   // id of element to receive info/error msg
                         reqd)   // error message if required, not required
                                 // if empty string 
{
  if (!document.getElementById) 
    return true;  // not available on this browser - leave validation to the server
  var elem = document.getElementById(ifld);
  if (!elem.firstChild)
    return true;  // not available on this browser 
  if (elem.firstChild.nodeType != node_text)
    return true;  // ifld is wrong type of node  

  if (emptyString.test(vfld.value)) {
    if (!emptyString.test(reqd)) {
      msg (ifld, "error", reqd);  
      setfocus(vfld);
      return false;
    }
    else {
      msg (ifld, "warn", "");   // OK
      return true;  
    }
  }
  return proceed;
}

// -----------------------------------------
//            validatePresent
// Validate if something has been entered
// Returns true if so 
// -----------------------------------------

function validatePresent(vfld,  // element to be validated
                         ifld,   // id of element to receive info/error msg
                         reqmsg) // error message for required, must not be empty
{
  var stat = commonCheck (vfld, ifld, reqmsg);
  if (stat != proceed) return stat;
  
  msg (ifld, "warn", "");   
  return true;
}

// -----------------------------------------
//               validateEmail
// Validate if e-mail address
// Returns true if so (and also if could not be executed because of old browser)
// -----------------------------------------

function validateEmail  (vfld,   // element to be validated
                         ifld,   // id of element to receive info/error msg
                         reqd)   // error message for required
{
  var stat = commonCheck (vfld, ifld, reqd);
  if (stat != proceed) return stat;

  var tfld = trim(vfld.value);  // value of field with whitespace trimmed off
  var email = /^[^@]+@[^@.]+\.[^@]*\w\w$/
  if (!email.test(tfld)) {
    msg (ifld, "error", "Please enter a valid e-mail address");
    setfocus(vfld);
    return false;
  }

  var email2 = /^[A-Za-z][\w.-]+@\w[\w.-]+\.[\w.-]*[A-Za-z][A-Za-z]$/
  if (!email2.test(tfld)) 
    msg (ifld, "warn", "Unusual e-mail address - check if correct");
  else
    msg (ifld, "warn", "");
  return true;
}


// -----------------------------------------
//            validateTelnr
// Validate telephone number
// Returns true if so (and also if could not be executed because of old browser)
// Permits spaces, hyphens, brackets and leading +
// -----------------------------------------

function validateTelnr  (vfld,   // element to be validated
                         ifld,   // id of element to receive info/error msg
                         reqd)   // error message for required
{
  var stat = commonCheck (vfld, ifld, reqd);
  if (stat != proceed) return stat;

  var tfld = trim(vfld.value);  // value of field with whitespace trimmed off
  var telnr = /^\+?[0-9 ()-]+[0-9]$/
  if (!telnr.test(tfld)) {
    msg (ifld, "error", "Please enter a valid phone number, e.g. 123-456-7890");
    setfocus(vfld);
    return false;
  }

  var numdigits = 0;
  for (var j=0; j<tfld.length; j++)
    if (tfld.charAt(j)>='0' && tfld.charAt(j)<='9') numdigits++;

  if (numdigits<6) {
    msg (ifld, "error", "Only" + numdigits + " digits - too short");
    setfocus(vfld);
    return false;
  }

  if (numdigits>14)
    msg (ifld, "warn", numdigits + " digits? - check if correct");
  else { 
    if (numdigits<10)
      msg (ifld, "warn", "Only " + numdigits + " digits - check if correct");
    else
      msg (ifld, "warn", "");
  }
  return true;
}

// -----------------------------------------
//             validateAge
// Validate person's age
// Returns true if OK 
// -----------------------------------------

function validateAge    (vfld,   // element to be validated
                         ifld,   // id of element to receive info/error msg
                         reqd)   // error message for required
{
  var stat = commonCheck (vfld, ifld, reqd);
  if (stat != proceed) return stat;

  var tfld = trim(vfld.value);
  var ageRE = /^[0-9]{1,3}$/
  if (!ageRE.test(tfld)) {
    msg (ifld, "error", "not a valid age");
    setfocus(vfld);
    return false;
  }

  if (tfld>=200) {
    msg (ifld, "error", "not a valid age");
    setfocus(vfld);
    return false;
  }

  if (tfld>110) msg (ifld, "warn", "Older than 110: check correct");
  else {
    if (tfld<7) msg (ifld, "warn", "Bit young for this, aren't you?");
    else        msg (ifld, "warn", "");
  }
  return true;
}

// -----------------------------------------
//              validateDate
// Validate date
// Returns true if OK 
// -----------------------------------------

function validateDate   (vfld,   // element to be validated
                          ifld,   // id of element to receive info/error msg
                          dlmt,   // valid date must be before the date limit
                                  // don't care if 'dlmt' is empty string
                          reqd)   // error message for required
{
  var stat = commonCheck (vfld, ifld, reqd);
  if (stat != proceed) return stat;
  
  var tfld = trim(vfld.value);
  var dateRE = /^[0-9]{2}\/[0-9]{2}\/[0-9]{4}$/;
  if (!dateRE.test(tfld)) {
    msg (ifld, "error", "Please use 'mm/dd/yyyy' format");
    setfocus(vfld);
    return false;
  }
  
  var dateElements = tfld.split("/");
  var mm = dateElements[0];  
  var dd = dateElements[1];
  var yyyy = dateElements[2];

  var fldDate = new Date(tfld);
  if ( fldDate.getMonth() + 1 != mm ||
       fldDate.getDate() != dd ||
       fldDate.getFullYear() != yyyy) {
    msg (ifld, "error", "Please enter a valid date");
    setfocus(vfld);
    return false;     
  }
  
  if (!emptyString.test(dlmt)) {
    var lmtDate = new Date(dlmt);
    if (fldDate > lmtDate) {
      // this error message depends on dlmt being set up correctly
      // by the caller
      msg (ifld, "error", "Must be at least 18 years old");
      setfocus(vfld);
      return false;
    }
  }
  
  msg (ifld, "warn", "");
  return true;
}

// -----------------------------------------
//             validateZipCode
// Validate zip code
// Returns true if OK 
// -----------------------------------------

function validateZipCode   (vfld,   // element to be validated
                            ifld,   // id of element to receive info/error msg
                            reqd)   // error message for required
{
  var stat = commonCheck (vfld, ifld, reqd);
  if (stat != proceed) return stat;
  
  var tfld = trim(vfld.value);
  var zipRE = /^[0-9]{5}(-[0-9]{4})?$/
  if (!zipRE.test(tfld)) {
    msg (ifld, "error", "Please enter a valid Zip Code");
    setfocus(vfld);
    return false;
  }
  
  msg (ifld, "warn", "");
  return true;
}
// -----------------------------------------
//             validateMonthDay
// Validate month and day
// Returns true if OK 
// -----------------------------------------
function validateMonthDay   (vfld,   // element to be validated
                            ifld,   // id of element to receive info/error msg
                            reqd)   // error message for required
{
  var stat = commonCheck (vfld, ifld, reqd);
  if (stat != proceed) return stat;
  
  var tfld = trim(vfld.value);
  var mdRE =  /^[0-9]{2}\/[0-9]{2}$/;
  if (!mdRE.test(tfld)) {
    msg (ifld, "error", "Please use 'mm/dd' format");
    setfocus(vfld);
    return false;
  }
  var dateElements = tfld.split("/");
  var mm = dateElements[0];  
  var dd = dateElements[1];
  
  if (dd > 31) {
    msg (ifld, "error", "Please enter a valid Month/Day");
    setfocus(vfld);
    return false;     
  }
  if (mm > 12) {
    msg (ifld, "error", "Please enter a valid Month/Day");
    setfocus(vfld);
    return false;     
  }
  
  msg (ifld, "warn", "");
  return true;
}
// -----------------------------------------
//             validateDropDown
// Validate drop down selection
// assumption, selectedIndex == 0 means not selected
// Returns true if OK 
// -----------------------------------------

function validateDropDown   (vfld,   // element to be validated
                              ifld,   // id of element to receive info/error msg
                              reqd)   // error message for required, mustn't be empty
{
  if (!document.getElementById) 
    return true;  // not available on this browser - leave validation to the server
  var elem = document.getElementById(ifld);
  if (!elem.firstChild)
    return true;  // not available on this browser 
       
  if (0 == vfld.selectedIndex) {
    msg (ifld, "error", reqd);
    return false;
  }
  
  msg (ifld, "warn", "");
  return true;
}