Question about plotting multi-plots in one page

[Chi <chi@xxxxxxxxx>]

Hi Ferret users
     I have several time-series mooring data collected at different 
depth. say at surface,
12m and 30m.  They are not suitable for interpolation on the depth axis 
as the depth values are
sparse and not uniformly distributed. For the measured variable,  say 
salinity,  I want to draw
a plot in which the horizontal axis represents time , and the vertical 
axis represents salinity, the data
measure at surface, 12m and 30m are represented by 3 different curves 
labeled with their
depth .
    Can anybody give me some clue? Any information will be appreciated.
     Thanks, Ding