[OS X TeX] Permission denied error with Alphatk and TeXshop

[John Burt]

I am attempting to set up Alphatk to work as the external editor for  
TeXshop. I have done this on another machine, but I can't seem to do  
it on my own machine. I used the "help applications" panel to select  
TeXshop as the help application for pdflatex (and the other relevant  
commands). But when I send my file from Alphatk to TeXshop I get an  
error message reading
couldn't execute "/Applications/TeX/TeXshop.app": permission denied.

Does anyone know how I can change the permissions of TeXshop so that  
Alphatk can call it?
thanks
Jophn