prstat output

hi all,
have a ksh script where i am doing a

prstat -m -u osuser 1 1 >> $FILE_NAME 

but for some reason it only writes 15 lines wheres when i run the same command manually from command prompt it prints out 60 lines.
why is it not writing the full 60 lines to the file ??

ta.

From prstat manual page:
When you specify the -c option or direct the output to a file, the default values for ntop and nbottom are 15 and 5.Use the -n option if you want more lines.