function fixH(one,two) {
 if (document.getElementById('container_box')) {
  var lh=document.getElementById('container_box').offsetHeight-200;
  document.getElementById('content_box').style.height=lh+"px";
 }
}


function valideerFormulier(frm) {
 var err1 = "";
 var retval;

 if(frm) {
  if(frm.voornaam.value == '')   err1 += '\n - Voornaam is verplicht/Firstname is mandatory';
  if(frm.achternaam.value == '') err1 += '\n - Achternaam is verplicht/Lastname is mandatory';
  if(frm.telefoon.value == '')   err1 += '\n - Telefoon is verplicht/Telephone is mandatory.';

  if(frm.email_werk.value == '') err1 += '\n - Email(werk) is verplicht/Email(work) is mandatory.';
  else if(checkEmail(frm.email_werk.value)==false) {
   err1 += '\n - Email(werk) is ongeldig/Email(work) is invalid.';
  }
 }
 else {
  err1='Form not found';
 }
 if(err1) {
  err2='De volgende fouten zijn gevonden/The following error(s) were found:' + 
           err1 + 
           '\n\nVerbeter de fouten en verzend opnieuw/Please correct these errors and resubmit.';
  alert(err2);
  retval = false;
 }
 else {
  retval=bevestigVerzenden();
 }
 return retval;
}

function bevestigVerzenden() {
 msg='Weet u zeker dat u het formulier wilt verzenden? \nAre you sure you want to submit the form?';
 if (confirm(msg)) {
  return true;
 }
 else {
  return false;
 }
}

function checkEmail(inputvalue) {
 var pattern=/^([a-zA-Z0-9_.-])+@([a-zA-Z0-9_.-])+\.([a-zA-Z])+([a-zA-Z])+/;
 if(pattern.test(inputvalue)) return true;
 else return false;
}