var originalValues = new Array();

function changeForm(){
  if(document.forms.length==2){
    originalValues['title'] = document.getElementById('preview_title').innerHTML;
    originalValues['description'] = document.getElementById('preview_description').innerHTML;
    originalValues['url'] = document.getElementById('preview_anchor').href;

    startTimer();
  }
}

function startTimer(){
  var timer = setTimeout('startTimer()', 400);
  updatePreview();
}

function updatePreview(){
  if(document.getElementById('preview_title').innerHTML != getElementValue('title')){
    document.getElementById('preview_title').innerHTML = getElementValue('title');
  }

  if(document.getElementById('preview_description').innerHTML != getElementValue('description')){
    document.getElementById('preview_description').innerHTML = getElementValue('description');
  }

  if(document.getElementById('preview_url').innerHTML != getElementValue('url')){
    document.getElementById('preview_url').innerHTML = getElementValue('url');
    document.getElementById('preview_anchor').href = 'http://'+encodeURI(getElementValue('url'));
  }

  if(Boolean(document.getElementById('preview_anchor').className)!= document.getElementById('eshop').checked){
    document.getElementById('preview_anchor').className = document.getElementById('eshop').checked ? 'eshop' : '';
  }
}

function getElementValue(id){
  var output = htmlentities(document.getElementById(id).value.replace(/^[a-z0-9]+\:\/\//i, '').trim());
  return (output ? output : originalValues[id].replace(/^[a-z0-9]+\:\/\//i, '').trim());
}