DataGraph plots both data sets and functions. A data set is part of a larger object known as a data series that contains the coordinate pairs, (x,y), together with drawing attributes such as color and style. Each series is identified by a series number, usually starting at one for the first series. Whenever data are added to the DataGraph, the appropriate series number must be specified.
Note: A series number is not the object identifier that is used in a data connection. Object identifiers are assigned by the operating system whereas series numbers are assigned by the script author. The object identifier for a series can be obtained by calling the getSeriesID method.
id=document.datagraph.getSeriesID(int);
The argument to this method is the series number. The return value is the object identifier.