/* Strip whitespace from the beginning and end of a string */
function trim(str) {
  return str.replace(/^\s+|\s+$/g,'');
}


/* Check if a form element is empty.
   If it is, display an alert box and focus on the element */
function isEmpty(formElement, message) {
  formElement.value = trim(formElement.value);
  _isEmpty = false;
  if (formElement.value == '') {
    _isEmpty = true;
    alert(message);
    formElement.focus();
  }
  return _isEmpty;
}


/* Configure status message to show */
function hidestatus(){
  var statusmsg="";
  window.status=statusmsg;
  return true;
}


/* Check entered customer contact data */   
function checkForm() { 
  var result= true;
  var name1=document.contactfrm.naam;
  var name2=document.contactfrm.adres;
  var name3=document.contactfrm.postcode;
  var name4=document.contactfrm.woonplaats;
  var name5=document.contactfrm.email;
  var name6=document.contactfrm.controle;
  var rname3exp = /^[1-9]\d{3}\s?[A-Z]{2}$/;
  var rname5exp = /^[a-z0-9\._%-]{2,}@[a-z0-9\._%-]{2,}\.[a-z]{2,4}$/;

  if (name1.value.length < 3) {
    alert("Er is geen naam ingevuld!");
    name1.focus();
    result= false;
    return result;
  }
  else if (name2.value.length < 5) {
    alert("Er is geen adres ingevuld!");
    name2.focus();
    result= false;
    return result;
  }
  else if (!name3.value.toUpperCase().match(rname3exp)) {
    alert("Geen of ongeldige postcode ingevuld!");
    name3.focus();
    result= false;
    return result;
  }
  else if (name4.value.length < 3) {
    alert("Er is geen woonplaats ingevuld!");
    name4.focus();
    result= false;
    return result;
  }
  else if (!name5.value.toLowerCase().match(rname5exp)) {
    alert("Geen of ongeldig e-mail adres ingevuld!");
    name5.focus();
    result= false;
    return result;
  }
  else if (name6.value.length < 5) {
    alert("Vul de controle code in!");
    name6.focus();
    result= false;
    return result;
  }   
  return result;
}