There are different shells. They tend to support different scripting languages.
The script you are trying to use appears to use the type of scripting syntax that is
similar to what's known as the "C" Shell, or "csh". That's likely why the file name
has the ".csh" extension. When I run the C shell, and try to source the script
you've supplied, it works just fine, no errors reported. You appear to be trying
to edit the script for something similar to the Bourne shell style of script syntax.
If you are using something more like the Bourne shell, which includes various other
types of shells, such as bash, you probably want SYBASE.sh instead. I allowed Sybase
to install in the default location, so for me
works just fine with bash.