/*
For input validation, by Yuqing Tang

*/
function isEmpty(afield)
{
	if (afield.value == null) return false;
	var re = /\s/g; //Match any white space including space, tab, form-feed, etc. 
	RegExp.multiline = true; // IE support
	var str = afield.value.replace(re, "");
	if (str.length == 0) {
		return true;
	} else {return false;}
} 
function isChecked(afield)
{
   	  var rv = false;
	  for (i = 0; i < afield.length; i++)
	   	  if (afield[i].checked) {rv = true; break;}
	  return rv;
}
function checkEmpty(afield, msg)
{
    if(isEmpty(afield)) {
      if (msg != null) alert(msg);
	  afield.focus();	  
	  return false;
    }
	return true;
}

function isNumber(aField)
{
	return (!isEmpty(aField) && !isNaN(aField.value));
}
function isEqual(field1, field2)
{
	return (field1.value == field2.value);
}
function inRange(item, min, max) 
{          
	if (!isNumber(item)) return false;
    var val = parseInt(item.value);
	return (val >= min && val <= max);
}