function handleFocus(item) {
  if( item=="newsletter_email" && document.getElementById(item).value=="email" ) {
    document.getElementById(item).value="";
  }
  if( item=="search_keyword" && document.getElementById(item).value=="trefwoord" ) {
    document.getElementById(item).value="";
  }
}

function handleBlur(item) {
  if( item=="newsletter_email" && document.getElementById(item).value=="" ) {
    document.getElementById(item).value="email";
  }
  if( item=="search_keyword" && document.getElementById(item).value=="" ) {
    document.getElementById(item).value="trefwoord";
  }
}

function conForm(formName) {
  bResult = true;
  errorMessage = "Oeps!\r\n\r\n";
  
  if(formName=="newsletter") {
    if(!isEmail(document.getElementById('newsletter_email').value)) {
      errorMessage += "- Ongeldig emailadres\r\n";
      bResult = false;
    }
  }
  
  if(formName=="search") {
    errorMessage += "De zoekoptie word nog niet ondersteund,\nprobeer het later nog eens...";
    bResult = false;
  }
  
  if(formName=="guestbook") {
    if(document.getElementById('naam').value=="") {
      errorMessage += "- Naam is niet gevuld\r\n";
      bResult = false;
    }
    if( document.getElementById('email').value!="" && !isEmail(document.getElementById('email').value) ) {
      errorMessage += "- Ongeldig emailadres\r\n";
      bResult = false;
    }
    if(document.getElementById('entry').value=="") {
      errorMessage += "- Opmerking is niet gevuld\r\n";
      bResult = false;
    }
  }
  
  if(formName=="creditart") {
    if(document.getElementById('aanvrager').value=="") {
      errorMessage += "- Aanvrager is niet gevuld\r\n";
      bResult = false;
    }
    if(document.getElementById('begunstigde').value=="") {
      errorMessage += "- Begunstigde is niet gevuld\r\n";
      bResult = false;
    }
  }
  
  if(formName=="inschrijving") {
    if(document.getElementById('initialen').value=="") {
      errorMessage += "- Voorletter(s) is niet gevuld\r\n";
      bResult = false;
    }
    if(document.getElementById('naam').value=="") {
      errorMessage += "- Achternaam is niet gevuld\r\n";
      bResult = false;
    }
    if(!isEmail(document.getElementById('email').value)) {
      errorMessage += "- Ongeldig emailadres\r\n";
      bResult = false;
    }
    if(document.getElementById('straat').value=="") {
      errorMessage += "- Straat is niet gevuld\r\n";
      bResult = false;
    }
    if(document.getElementById('nummer').value=="") {
      errorMessage += "- Huisnummer is niet gevuld\r\n";
      bResult = false;
    }
    if(document.getElementById('postcode').value=="") {
      errorMessage += "- Postcode is niet gevuld\r\n";
      bResult = false;
    }
    if(document.getElementById('plaats').value=="") {
      errorMessage += "- Woonplaats is niet gevuld\r\n";
      bResult = false;
    }
  }
	
	if(formName=="provence") {
    if(document.getElementById('naam').value=="") {
      errorMessage += "- Naam is niet gevuld\r\n";
      bResult = false;
    }
    if(!isEmail(document.getElementById('email').value)) {
      errorMessage += "- Ongeldig emailadres\r\n";
      bResult = false;
    }
  }
  
  if(!bResult) {
    alert(errorMessage);
  }
  return bResult;
}


function isEmail(email) {
  required = true;
  if (required==undefined) {   // if not specified, assume it's required
    required=true;
  }
  if (email==null) {
    if (required) {
      return false;
    }
    return true;
  }
  if (email.length==0) {  
    if (required) {
      return false;
    }
    return true;
  }
  if (! allValidChars(email)) {  // check to make sure all characters are valid
    return false;
  }
  if (email.indexOf("@") < 1) { //  must contain @, and it must not be the first character
    return false;
  } else if (email.lastIndexOf(".") <= email.indexOf("@")) {  // last dot must be after the @
    return false;
  } else if (email.indexOf("@") == email.length) {  // @ must not be the last character
    return false;
  }
  return true;
}

function allValidChars(email) {
  var parsed = true;
  var validchars = "abcdefghijklmnopqrstuvwxyz0123456789@.-";
  for (var i=0; i < email.length; i++) {
    var letter = email.charAt(i).toLowerCase();
    if (validchars.indexOf(letter) != -1)
      continue;
    parsed = false;
    break;
  }
  return parsed;
}

function galleryForm(galleryUrl) {
  // build the new url
  onderwerp = document.getElementById('onderwerp').options[document.getElementById('onderwerp').selectedIndex].value;
  materiaal = document.getElementById('materiaal').options[document.getElementById('materiaal').selectedIndex].value;
  kunstenaar = document.getElementById('kunstenaar').options[document.getElementById('kunstenaar').selectedIndex].value;
  url = galleryUrl + "/" + onderwerp + "/" + materiaal + "/" + kunstenaar;
  location.href = url;
}