problems with mic on FSX multiplayer

[microflyboy]

:-/ I can't get my mic to work in multiplayer FSX. It works perfectly well when using MSN Messenger so I know that there is no problem with connections, hardware, software etc.
Is there a programme I need to download first, such as Teamspeak, as I did for FS 2002 ? I can hear instructions from ATC but cannot reply even though Coms 1 is set to the frquency. Currently this is spoiling my enjoyment of multiplayer. Can anyone help ?

[alrot]

did you hit the key

[microflyboy]

Many thanks, that worked a treat! you wouldn't believe the time I've spent trying to sort this out! I had a most enjoyable flight on multiplayer tonight. Thanks for the reply. aka G-MZLG