Hi Kevin,
there is a JavaScript function,
SetSessionValue('name','value');
which you can call from the browser. So you could trap all keydowns, (like you're doing for F8).
But that's not really the right answer is is. No, what you need to do is extend the URL you're using so
that the "current value" of the field is passed as a parameter in the URL.
so, something like (untested...)
'jQuery(document).bind(<39>keydown<39>, <39>F8<39>, function()<123>window.open(<39>ChartOfAccountsLookup?plu=<39> + FieldValue(this,1),<39>_self<39>)<125>);'
You may need to experiment with the FieldValue part - my guess is you may need to put in the actual field id etc...
Cheers
Bruce