Hi,

...

Sorry if this is wandering a little off topic, but what's a `beat'? What stops

A writes `A'
A waits a beat

A short wait. Just long enough to let things settle so you get reliable data. It's really a musical term that's I've absconded with...

This won't work. A doesn't know how long to wait because it doesn't know how quickly B might get around to trampling the `A'.

Ralph.