//-----------------------------------------------------------------------------------------------
// Common Functions
//----------------------------------------------------------------------------------------------- 



function confirmActionGeneric()
{
	return confirm("Are you sure you wish to save this data?");
}


function confirmAction(message)
{
	return confirm(message);
}



//-----------------------------------------------------------------------------------------------
// form validation functions for updating and adding new records
//------------------------------------------------------------------------------------------------


var defaultEmptyOK = false

function isDigitEvent()
{
	return ((event.keyCode >= 48) && (event.keyCode <= 57))
}


function isInteger (s)
{

var i;

if (isEmpty(s))
	if (isInteger.arguments.length == 1) return defaultEmptyOK;
    else return (isInteger.arguments[1] == true);
    for (i = 0; i < s.length; i++)
	{
		// Check that current character is number.
		var c = s.charAt(i);
		if (!isDigit(c)) return false;
	}
// All characters are numbers.
return true;
}

//------------------------------------------------------------------------------------------------

// Returns true if character c is a digit
// (0 .. 9).

function isDigit (c)
{
	return ((c >= "0") && (c <= "9"));
}

//------------------------------------------------------------------------------------------------

function isEmpty(s)
{
	return ((s == null) || (s.length == 0))
}
//------------------------------------------------------------------------------------------------

function isFloat (s)

{
	var i;
	var decimalPointDelimiter = "."
	var seenDecimalPoint = false;

    if (isEmpty(s)) 
       if (isFloat.arguments.length == 1) return false;
       else return (isFloat.arguments[1] == true);

    if (s == decimalPointDelimiter) return false;

    // Search through string's characters one by one
    // until we find a non-numeric character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number.
        var c = s.charAt(i);

        if ((c == decimalPointDelimiter) && !seenDecimalPoint) seenDecimalPoint = true;
        else if (!isDigit(c)) return false;
    }

    // All characters are numbers.
    return true;
}

//------------------------------------------------------------------------------------------------

// isNegativeInteger (STRING s [, BOOLEAN emptyOK])
// 
// Returns true if string s is an integer < 0.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function isNegativeInteger (s)
{   var secondArg = defaultEmptyOK;

    if (isNegativeInteger.arguments.length > 1)
        secondArg = isNegativeInteger.arguments[1];

    // The next line is a bit byzantine.  What it means is:
    // a) s must be a signed integer, AND
    // b) one of the following must be true:
    //    i)  s is empty and we are supposed to return true for
    //        empty strings
    //    ii) this is a negative, not positive, number

    return (isSignedInteger(s, secondArg)
         && ( (isEmpty(s) && secondArg)  || (parseInt (s) < 0) ) );

}

//------------------------------------------------------------------------------------------------

// isIntegerInRange (STRING s, INTEGER a, INTEGER b [, BOOLEAN emptyOK])
// 
// isIntegerInRange returns true if string s is an integer 
// within the range of integer arguments a and b, inclusive.
// 
// For explanation of optional argument emptyOK,
// see comments of function isInteger.


function isIntegerInRange (s, a, b)
{   if (isEmpty(s)) 
       if (isIntegerInRange.arguments.length == 1) return defaultEmptyOK;
       else return (isIntegerInRange.arguments[1] == true);

    // Catch non-integer strings to avoid creating a NaN below,
    // which isn't available on JavaScript 1.0 for Windows.
    if (!isInteger(s, false)) return false;

    // Now, explicitly change the type to integer via parseInt
    // so that the comparison code below will work both on 
    // JavaScript 1.2 (which typechecks in equality comparisons)
    // and JavaScript 1.1 and before (which doesn't).
    var num = parseInt (s);
    return ((num >= a) && (num <= b));
}

//------------------------------------------------------------------------------------------------

// isSignedFloat (STRING s [, BOOLEAN emptyOK])
// 
// True if string s is a signed or unsigned floating point 
// (real) number. First character is allowed to be + or -.
//
// Also returns true for unsigned integers. If you wish
// to distinguish between integers and floating point numbers,
// first call isSignedInteger, then call isSignedFloat.
//

// Does not accept exponential notation.
//
// For explanation of optional argument emptyOK,
// see comments of function isInteger.

function isSignedFloat (s)

{   if (isEmpty(s)) 
       if (isSignedFloat.arguments.length == 1) return defaultEmptyOK;
       else return (isSignedFloat.arguments[1] == true);

    else {
        var startPos = 0;
        var secondArg = defaultEmptyOK;

        if (isSignedFloat.arguments.length > 1)
            secondArg = isSignedFloat.arguments[1];

        // skip leading + or -
        if ( (s.charAt(0) == "-") || (s.charAt(0) == "+") )
           startPos = 1;    
        return (isFloat(s.substring(startPos, s.length), secondArg))
    }
}
//------------------------------------------------------------------------------------------------

// removes all spaces from a string

function trim (s)
{
	var iLen = s.length;
	var sOut = "";
	var chr = "";

	for (var i=0; i<iLen; i++)
	{
		chr = s.charAt (i); 
		if (chr!=" ")
		{
			sOut = sOut + chr; 
		}
	}
	return sOut;
}



//------------------------------------------------------------------------------------------------

// checks for valid email address

function emailCheck (emailStr) {
/* 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 +")*$")


/* Finally, let's start trying to figure out if the supplied address is
   valid. */

/* 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]

// 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
var domainArray=domain.match(domainPat)
if (domainArray==null) {
	alert("The domain name doesn't seem to be valid.")
    return false
}

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

/* Now we need to break up the domain to get a count of how many atoms
   it consists of. */
var atomPat=new RegExp(atom,"g")
var domArr=domain.match(atomPat)
var len=domArr.length
if (domArr[domArr.length-1].length<2 || 
    domArr[domArr.length-1].length>4) {
   // the address must end in a two letter or three letter word.
   alert("The address must end in a three or four-letter domain, or two letter country.")
   return false
}

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

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


//------------------------------------------------------------------------------------------------

// checks for valid postcode

function validatePostCode(postCode)
{ 

   var pc = trim(postCode);

   if (!(isAlphaNumeric(pc)))
   {
      alert ("postcode contains invalid characters");
      return false;
   }

   if (pc.length < 5 || pc.length > 10)
   {
      alert("invalid postcode - wrong length");
      return false;
   }
   return true;
 }

// checks that input string is alphanumeric

function isAlphaNumeric(s)
{
   var validChars = "abcdefghijklmnopqrstuvwxyz0123456789";
   s = s.toLowerCase();
   
   for (var i = 0; i < s.length; i++) 
   {
      if (validChars.indexOf(s.charAt(i)) == -1)
      return false;
   }
   return true;
}