[Ilugc] Sound not working in debian lenny

[Azhagu selvan]

Hi,
   I am using Debian Lenny. Earlier,when i connect my headphone to the PC, i
was able hear the sound but my mic didn't capture any sound. To do some
voice chat, i tried changing the volume levels, changed switches,
mute/unmute certain controls in the volume control( i played, i don't know
what i have done exactly).Now, all of a sudden the sound from the PC stopped
and my mic started to work. Now whatever my mic captures, it comes straight
back to the speaker. I can't hear any other audio playback or anything in my
speaker, just only the mic input. I tried "alsaconf"but it doesn't help. All
volume controls are in full level. Can anyone point out what's wrong in my
configuration now?

Regards,

Azhaguselvan.SP