// 
// Verwijder voorloppspaties
function LTrim(str)
{
while (str.substring(0,1) == ' ')
  {str = str.substr(1,str.length-1);}
return str
}

//
// Verwijder spaties aan eind
function RTrim(str)
{
if (str.substr(str.length-1,1) == ' ')
  {
  do
    {
    str = str.substr(0,str.length-1);
    }
  while (str.substr(str.length-1,1) == ' ')
  };

return str;
}

//
// Character is cijfer
//
function CharIsDigit(c)
{
  if ('0123456789'.indexOf(c) <0 ) {return false;};
  return true;
}

//
// Character is letter
//
function CharIsAlf(c)
{
  if ('ABCDEFGHIJKLMNOPQRSTUVWXYZ'.indexOf(c) <0 ) {return false;};
  return true;
}

//
// Tkest is geldige nederlandse postcode
//
function ValidZipCodeNL(str)
{
rv = new String();
rv = "OK"

str = str.toUpperCase();
//str=str.trim(str);
str = LTrim(str);
str = RTrim(str);

// check minimum length
if (str.length < 6) {rv = "NO";};

// check maximum length
if (str.length > 7) {rv = "NO";};

// check 1e 4 posities cijfers
i = 0;
do
  {
  if (!CharIsDigit(str.substr(i,1))) {rv = "NO";};
  i+=1;
  }
while (i <=3);

// check 1e positie 1 of hoger
if ('123456789'.indexOf(str.substr(0,1)) <0 ) {rv = "NO";};

// check laatste 2 posities hoofdletters
if (!CharIsAlf(str.substr(str.length-1,1))) {rv = "NO";};
if (!CharIsAlf(str.substr(str.length-2,1))) {rv = "NO";};

if (rv == "OK") {return true}
else {return false;};
}

//
//Tekst is geldig emailadres
//
function ValidEmailAddress(str)
{
var posAmp
var posDot
rv = new String();
reason = new String();
rv = "OK";

// len=0 is ok
if ((str == "") || (str == null)) {
  alert (str.length);
  return true;
}

// check minimum length
if (str.length < 6)
  rv = "NO";

//check & is present
posAmp = str.indexOf('@')
if (posAmp <=0)
  rv = "NO";

//check . is present
posDot = str.lastIndexOf('.')
if (posDot <=0)
  rv = "NO";

//check at least one . appears after @.
if (posDot < posAmp)
  rv = "NO";

if (rv == "NO")
  {
  return false;
  }
else
  {
  return true;
  }

}

//
// Tekst mag niet leeg zijn
//
function emptyvalidation(entered, alertbox)
{
// Emptyfield-Validation (c) Henrik Petersen / NetKontoret
// Explained at www.echoecho.com/jsforms.htm
// Please do not remove the this line and the two lines above.
with (entered)
{
if (value==null || value=="")
{if (alertbox!="") {alert(alertbox);} return false;}
else {return true;}
}
}