// JavaScript Document
<!-- this pop-up window function //-->
function popUpWindow(URLStr, left, top, width, height)
{
  if(popUpWin)
  {
    if(!popUpWin.closed) popUpWin.close();
  }
//  popUpWin = open(URLStr, 'popUpWin', 'toolbar=no,location=no,directories=no,status=no,menub ar=no,scrollbar=no,resizable=no,copyhistory=yes,width='+width+',height='+height+',left='+left+', top='+top+',screenX='+left+',screenY='+top+'');
  popUpWin = open(URLStr, 'popUpWin', 'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=1,resizable=no,copyhistory=yes,width='+width+',height='+height+',left='+left+', top='+top+',screenX='+left+',screenY='+top+'');
}
<!-- end pop-up window function //-->

<!-- validate form entries function //-->
function validateEntry(obj) {
	if((obj.f_required_rent.value.length < 1) || isNaN(obj.f_required_rent.value)) {
		alert("please enter valid rental amount");
		obj.f_required_rent.focus();
		return false
	}
	else 
		return true;
}
<!-- end validate form entries function //-->