function is_emailadres(str)
{
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (filter.test(str)) 
  {
    return true;
  }
  else
  {
    return false;
  }
}

function maskKeyPress(objEvent) {
	var iKeyCode = window.event ? objEvent.keyCode : objEvent.which;
  // alleen cijfers, backspace, delete, + en -
  if((iKeyCode>=48 && iKeyCode<=57) || iKeyCode==0 || iKeyCode==8 || iKeyCode==45 || iKeyCode==43) return true;
  return false;
}

function update_pc()
{
  if ((document.getElementById('txt_pc_nr').value/1) && document.getElementById('txt_pc').value!='' && document.getElementById('txt_letterpc').value!='' && document.getElementById('txt_pc_nr').value!='')
  {
    xajax_getStreet_City(document.getElementById('txt_pc').value, document.getElementById('txt_letterpc').value, document.getElementById('txt_pc_nr').value);
  }
}