// validate.js

<!--

 function emailCheck(str)
 {
  var emailStr = str.toLowerCase();

  /* The following variable tells the rest of the function whether or not
  to verify that the address ends in a two-letter country or well-known
  TLD.  1 means check it, 0 means don't. */
  var checkTLD=1;

  // list of known TLDs that an e-mail address must end with. */
  var knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;

  /* The following pattern is used to check if the entered e-mail address
  fits the user@domain format.  It also is used to separate the username
  from the domain. */
  var emailPat=/^(.+)@(.+)$/;

  /* The following string represents the pattern for matching all special
  characters.  We don't want to allow special characters in the address. 
  These characters include ( ) < > @ , ; : \ " . [ ] */
  var specialChars="\\(\\)><@,;:\\\\\\\"\\.\\[\\]";

  /* The following string represents the range of characters allowed in a 
  username or domainname.  It really states which chars aren't allowed.*/
  var validChars="\[^\\s" + specialChars + "\]";

  /* The following pattern applies if the "user" is a quoted string (in
  which case, there are no rules about which characters are allowed
  and which aren't; anything goes).  E.g. "jiminy cricket"@disney.com
  is a legal e-mail address. */
  var quotedUser="(\"[^\"]*\")";

  /* The following pattern applies for domains that are IP addresses,
  rather than symbolic names.  E.g. joe@[123.124.233.4] is a legal
  e-mail address. NOTE: The square brackets are required. */
  var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;

  /* The following string represents an atom (basically a series of non-special characters.) */
  var atom=validChars + '+';

  /* The following string represents one word in the typical username.
  For example, in john.doe@somewhere.com, john and doe are words.
  Basically, a word is either an atom or quoted string. */
  var word="(" + atom + "|" + quotedUser + ")";

  // The following pattern describes the structure of the user
  var userPat=new RegExp("^" + word + "(\\." + word + ")*$");

  /* The following pattern describes the structure of a normal symbolic
  domain, as opposed to ipDomainPat, shown above. */
  var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");

  /* Begin with the coarse pattern to simply break up user@domain into
  different pieces that are easy to analyze. */
  var matchArray=emailStr.match(emailPat);

  if( matchArray==null )
   {
    /* Too many/few @'s or something; basically, this address doesn't
    even fit the general mould of a valid e-mail address. */
    alert("Email address seems incorrect (check @ and .'s)");
    return false;
   }

  var user=matchArray[1];
  var domain=matchArray[2];

  // Start by checking that only basic ASCII characters are in the strings (0-127).
  for( i=0; i<user.length; i++ )
   {
    if( user.charCodeAt(i) > 127 )
     {
      alert("Ths username contains invalid characters.");
      return false;
     }
   }

  for( i=0; i<domain.length; i++ )
   {
    if( domain.charCodeAt(i) > 127 )
     {
      alert("Ths domain name contains invalid characters.");
      return false;
     }
   }

  // See if "user" is valid 
  if( user.match(userPat) == null )
   {
    // user is not valid
    alert("The username doesn't seem to be valid.");
    return false;
   }

  /* if the e-mail address is at an IP address (as opposed to a symbolic
  host name) make sure the IP address is valid. */
  var IPArray=domain.match(ipDomainPat);
  if( IPArray != null )
   {
    // this is an IP address
    for( var i=1;i<=4;i++ )
     {
      if( IPArray[i] > 255 )
       {
        alert("Destination IP address is invalid!");
        return false;
       }
     }

    return true;
   }

  // Domain is symbolic name.  Check if it's valid.
  var atomPat=new RegExp("^" + atom + "$");
  var domArr=domain.split(".");
  var len=domArr.length;

  for( i=0;i<len;i++ )
   {
    if(domArr[i].search(atomPat)==-1)
     {
      alert("The domain name does not seem to be valid.");
      return false;
     }
   }

  /* domain name seems valid, but now make sure that it ends in a
  known top-level domain (like com, edu, gov) or a two-letter word,
  representing country (uk, nl), and that there's a hostname preceding 
  the domain or country. */

  if(checkTLD && domArr[domArr.length-1].length!=2 && 
     domArr[domArr.length-1].search(knownDomsPat)==-1)
   {
    alert("The address must end in a well-known domain or two letter " + "country.");
    return false;
   }

  // Make sure there's a host name preceding the domain.
  if( len < 2 )
   {
    alert("This address is missing a hostname!");
    return false;
   }

  // If we've gotten this far, everything's valid!
  return true;
 }

 function numbersOnly( inpObj )
 {
  if( inpObj.match(/^\d+$/) ) return(true);
  return(false);
 }

 function checkTaxRate(val)
 {
  return /^0\.\d{4}$/.test(val);
 }

 function checkDecimals(value,min,max)
 {
  // Accepts number with decimal but it must have at least the min and at most the max places after the decimal
  var re = new RegExp("^-?\\d+\\.\\d{" + min + "," + max + "}?$");
  return re.test(value);
 }

 // return a number of checked checkboxes that all start with a
 // similar string such as "course_" -- this makes form validation
 // easier when you MUST have at least one item checked to submit
 function CheckboxesChecked( inpName )
 {
  var count = 0;

  var len = inpName.length;

  var inp = document.getElementsByTagName("input");
  if( inp[0] == null ) return(-1);

  for( var i = 0; i < inp.length; i++ )
   {
    if( inp[i].type != "checkbox" ) continue;
    if( inp[i].name.substr(0,len) != inpName ) continue;
    if( inp[i].checked ) count++;
   }

  return(count);
 }

//-->