OK, I don't immediately see a problem there...
but I haven't been around Sun OS in quite some time, and it's seems there are some differences in the ksh implementation..
Can you verify that the ksh shell is actually present (i.e. is there are /usr/bin/ksh ?)
Also, you can try this version (same link, new file)
Not the change is only on the first line, to force using the traditional version of ksh as suggested here:
I'm not sure it applies here because you seem to be on Solaris 9, not 11 (SunOS5.9 == Solaris 9) .. but worth a try anyway.
A final note; it is possible that somehow the script itself got corrupted during transfer to you... how did you get it to your machine?
Did you by any chance open it in a browser, select the text and past it into a local file (editor window)? THat can cause problems...