window.onerror = customHandler; //silentHandler; 
//window.onresize = ;
//window.onload = ;

function addHandlers()
{
  var ctl = document.getElementById('checksub');
  if (ctl != null)
	{
		ctl.onclick = clearChecksub;
	}
}

function clearChecksub()
{
	var ctl = document.getElementById('checksub');
	if (ctl != null) ctl.value = '';
}

function defaultHandler() {return false}
function silentHandler()  {return true}
function customHandler(desc,page,line,chr)  {
  alert(
    'JavaScript error occurred! \n'
    +'\nError description: \t'+desc
    +'\nPage address:      \t'+page
    +'\nLine number:       \t'+line
  )
  return true;
}