[TxMt] auto save on focus change

[Donald Huebschman]

I am working in two windows (ruby), one the parent class of the  
other. I am editing in the parent class and running in the subclass.  
When I change my focus from the parent to sub to run, the parent does  
not get saved. I will assume that save of change of focus happens  
when focus changes to another application.

I would like to see the save on focus change apply to textmate  
windows/documents.

How do I tell if a document is dirty and requires saving?

Thanks
Don