I'm trying to set up my .vimrc to automatically load a Taglist session
files in my current working directory, but I can only get errors like
the plugin isn't loaded (though :TlistSessionLoad works fine by hand).
Can anyone show me where I'm going wrong and how to do this?

Thanks in advance for any help.

# .vimrc:
if filereadable(getcwd() . "/.taglist")
TlistSessionLoad ".taglist"
endif

# console:
$ vim
Error detected while processing /home/username/.vimrc:
line 58:
E492: Not an editor command: TlistSessionLoad ".taglist"
Press ENTER or type command to continue