// ----------------------------------------------------------------------
// 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.
// ----------------------------------------------------------------------

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(vfld)
{
  glb_vfld.focus()
}

function setfocus(vfld)
{
  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_msg = document.getElementById('evil_output');
  elem_msg.firstChild.nodeValue = dispmessage;
  elem_msg.className = msgtype;   // set the CSS class to adjust appearance of message

  //document.forms.registration.inf_email.className = msgtype;

  var elem = document.getElementById(fld);
  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)   // true if required
{
  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 (reqd) {
      msg (ifld, "error",  f_err_error + ", " + f_err_required);
      setfocus(vfld);
      return false;
    }
    else {
      msg (ifld, "okee", "");   // 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
{
  var stat = commonCheck (vfld, ifld, true);
  if (stat != proceed) return stat;

  msg (ifld, "okee", "");
  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)   // true if 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",  f_err_error + ", " + f_err_email_error);
    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",  f_err_warn + ", " + f_err_email_warn);
    }
  else {
    msg (ifld, "okee", "");
    }
  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)   // true if 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", f_err_error + ", " + f_err_tel_error + " (" + f_err_input_invalid + ") " + f_err_input_accepted + "( ) - +");
    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", f_err_error + ", " + f_err_tel_error + " (" + f_err_input_tooshort + ")");
    setfocus(vfld);
    return false;
  }

  if (numdigits>14) {
    msg (ifld, "warn", f_err_warn + ", " + f_err_tel_warn + " (" + f_err_input_long + ")");
    }
  else {
    if (numdigits<10) {
      msg (ifld, "warn", f_err_warn + ", " + f_err_tel_warn + " (" + f_err_input_short + ")");
      }
    else {
      msg (ifld, "okee", "");
      }
  }
  return true;
};

// -----------------------------------------
//            validateNumber
// Validate number
// Returns true if so (and also if could not be executed because of old browser)
// -----------------------------------------

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

  var tfld = trim(vfld.value);
  if (!PostCheckNumber(tfld)) {
    msg (ifld, "error", f_err_error + ", " + f_err_input_number);
    setfocus(vfld);
    return false;
  }
  else {
    msg (ifld, "okee", "");
  }

  return true;
};

// -----------------------------------------
//            validateAlpha
// Validate text
// Returns true if so (and also if could not be executed because of old browser)
// -----------------------------------------

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

  var tfld = trim(vfld.value);
  if (!PostCheckText(tfld)) {
    msg (ifld, "error", f_err_error + ", " + f_err_input_alpha);
    setfocus(vfld);
    return false;
  }
  else {
    msg (ifld, "okee", "");
  }

  return true;
};