Retroactively pairing a tow and glider

Sometimes a tow plane and a glider are launched independently through Quick Start rather than through the Aerotow form, and only afterwards is it clear (or worth recording) that one towed the other. The Edit form on any flight includes a "pair with a tow" dropdown listing that day's other flights - pick one to link them, or clear it to unlink.

Once paired, both flights show each other's details (aircraft, timing, duration) wherever the Tow column appears - looking at the glider shows the tow's info, and looking at the tow shows the glider's, symmetrically.