[gradsusr] Regrid Help

[Emily Parker Wilson]

Hello I am trying to regrid in GrADS and i am getting the error message...
No hardcopy metafile open
All files closed; all defined objects released;
All GrADS attributes have been reinitialized
73 90 -90
re(swvl1.1,73,LINEAR,-90,2.5,145,LINEAR,-180,2.5,ba)
Operation Error:  Error from re function
Operation Error:  Error from regrid2 function
  Error ocurred at column 1
DEFINE error:  Invalid expression. 
Operation Error:  Error from re function
  Error ocurred at column 1
DEFINE error:  Invalid expression. 
ga-> quit
Hardcopy output file is closed 
GX package terminated 

the grad script i am using looks like this...
*  DATA TO BE REGRIDDED
*
  'sdfopen ecmwfsoilw.nc'
*
  'enable print grads.outfile'
  'clear'
*
* DEFINE OUTPUT FILE
*
  'set fwrite ecmwfsoilw.regrid.nc'
*
* OUTPUT TO THE FILE
*
  'set gxout fwrite'
*
* WRITE 228 MONTHS
*
*  'set t 1 248'
*
* REGRID THE DATA
*
*  'd regrid2(swvl1,5.0,5.0,bs_p1,-177.5,-87.5)'
* 
*     
 'set lat -180 180'
 'set lon -90 90'

* 'd re(swvl1,144,'linear',-192,2.5,73,'linear',94,2.5,bs)'

* 'd re(swvl1,2.5,2.5,bs)'

  'newgrid=regrid2(swvl1.1,2.5)'
  'define regrid2=re(swvl1.1,2.5,2.5)'

* 'define newvar=re(swvl1,144,'linear',2.5,192,73,'gaus',1,94)'
* 'd newvar'
*
  'print'

can someone please tell me what i am doing wrong?
Thanks so much,
Emily