Temperature Graphs

Hey all,
 I'm trying to monitor some temperatures from Windows boxes and I have
the external script set up to send the message to Xymon, and it's
trying to create the graph, but It's not seeing any data, even over
the course of several hours worth of data.

 Does anyone know the exact formatting necessary to create the graphs?

 Also, is it possible to graph multiple items on one graph?

Thanks!
--Pat