Now you just enter the key you wanna assign to the action between the On/On End.
It's a pity but key-combinations aren't possible as far as I know...
Here's an example with 3 actions and 3 keys:
On (Key: F)
Get URL ("http://www.flashkit.com")
End On
On (Key: f)
Get URL ("http://www.flashkit.com")
End On
On (Key: M)
Get URL ("http://www.microsoft.com")
End On
On (Key: m)
Get URL ("http://www.microsoft.com")
End On
On (Key: N)
Get URL ("http://www.netscape.com")
End On
On (Key: n)
Get URL ("http://www.netscape.com")
End On