Making composites of data for specific OLR values within an certain area

[Jason Snyder]

I am trying to make a script that composites pressure values from dates
when OLR values over a certain area (latitude range: 5S to 5N and
longitude: 120E and 120W) are below a certain value.  I tried using this
script and it did not seem to work properly.  What should I do to make
this script so that I can make this script work properly?  Also how can I
composite wind data at specific pressure levels such as 850 mb and 500 mb
based on this script?
'sdfopen olr.day.mean.nc'
'sdfopen pres.sfc.1993.nc'
'set t 6790'
'define presa = 0'
'define number = 0'
count = 6790
while (count < 12267)
  'set t 'count
  'define olra = aave(olr,lon=120,lon=240,lat=-5,lat=5)'
  if (olra < 230)
     'define presb = pres.2'
     'define n=1'
  else
     'define presb = 0'
     'define n = 0'
  endif
'define presa = presa + presb'
'define number = number + n'
count = count + 1
endwhile
'define presavg=presa'


If someone has any suggestions on what to do with this script to make it
composite wind/pressure data for days where the average OLR values within
the area 120 W to 120 E and 15S to 15N, is less than 234, that would be
greatly appreciated.

Thanks,

Jason