function happy_browser_addEventListener(event_name, function_ptr, capturing)
{
  document.addEventListener(event_name, function_ptr, capturing);
}

function happy_browser_removeEventListener(event_name, function_ptr, capturing)
{
  document.removeEventListener(event_name, function_ptr, capturing);
}

function happy_browser_preventDefault(event)
{
  event.preventDefault();
}

function happy_browser_stopPropagation(event)
{
  event.stopPropagation();
}

function happy_browser_clientX(event)
{
  return event.clientX;
}

function happy_browser_clientY(event)
{
  return event.clientY;
}