code: function isDataMissing(iStart, iEnd) {
  			var i;
  			for (i = iStart; i < iEnd; i += 1) {
  				if (aElements[i] === undefined) {
  					return true;
  				}
  			}
  			return false;
  		}
docs: Checks whether aElements contains at least one <code>undefined</code> entry within the given start (inclusive) and end (exclusive).