Auto-call forward on no answer

Dear Friends

I’m using asterisk 1.8.11.0 engine, and have some extensions working. If a call comes in and the extension doesn’t answer (or is busy) there should be a way to automatically transfer the call to another extension but its not clear where one configures this in the GUI. I did a search on Google but couldn’t find any straightforward instructions for this. How is it done?

Please help me

wrong forum as You’re using some GUI-flavoured Asterisk (some one AsteriskNow; FreePBX or whatever)

Specifically, for FreePBX, you want freepbx.org/forums/

AsteriskGUI is considered a dead product.