[xubuntu-users] Marking a text file as executable

[John R. Sowden]

I have a text file that appears to be a script to run an acct app.  I 
cannot execute it, and it shows in the file manager as a 'plain text file'.

Right clicking on properties then permissions, there is no check box for 
'make executable'.

The text file starts with #! /usr/bin/wish

How do make this file executable? I tried on a root file manager, no 
change.  The files is owned by me for r/w/.

John