How to make multiple plots, arrange them vertically and output in onepicture?

[chi <chi@xxxxxxxxx>]

Hi there
     I'm building a LAS site for mooring data. I'm wondering how to let 
ferret
make a plot for each variable the user selected , say "U-wind", "Air 
temperature", "SST".
Then arrange the three plots vertically and output them in one picture?
     What I want to do is just like the LAS site of  "Tropical 
Atmosphere Ocean Project" did.
You can take a look at http://www.pmel.noaa.gov/tao/jsdisplay/ , and 
select "Time series plots".
     Any information will be highly appreciated.
     Thanks a lot, Ding