Error in plotskew.gs

[Leopoldo Alvarez]

Dear grads-users,

I am trying to use plotskew.gs, i have followed the steps of ->
http://moe.met.fsu.edu/~rhart/skew.html#usage (Robert Hart)

i use ->

set lon -16
set lat 28
set lev 1050 100

and this is the error ->

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ga-> plotskew.gs
Syntax Error:  Invalid Operand
  'snddewp' not a variable or function name
  Error ocurred at column 2
DEFINE error:  Invalid expression.
Drawing temperature sounding.
Drawing dewpoint sounding.
Syntax Error:  Invalid Operand
  'dewpx' not a variable or function name
  Error ocurred at column 1
DISPLAY error:  Invalid expression
  Expression = dewpx
Syntax Error:  Expected operand or '('
Operation Error:  Error from maskout function
  Error ocurred at column 1
DISPLAY error:  Invalid expression
  Expression = maskout(lev,+300)
SET error:  Missing or invalid arguments for LEV option
Display command error:  No expression provided
Syntax Error:  Invalid Operand
  'snddewp' not a variable or function name
  Error ocurred at column 1
DISPLAY error:  Invalid expression
  Expression = snddewp
Non-numeric args to numeric operation
Error occurred processing function arguments
  Error occurred on line 1984
  In file plotskew.gs
  Error occurred on line 2219
  In file plotskew.gs
  Error occurred on line 998
  In file plotskew.gs
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Leopoldo Alvarez

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Leopoldo Alvarez
General Manager - Tecnico Investigator
Meteorology and Oceanographic Studies Institute
Canary Islands - Spain
E-mail: lalvarez at idemoc.com
Tlfno: (+34) 600 253 237
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