After much googling I found the answer to getting the internal mic to work.
First of all, when I type alsamixer -c0 my sound card is called HDA Intel PCH and the chip is Intel CougarPoint HDMI. If yours isn't this it might not work.
As root, edit (create if it doesn't exist) /etc/modprobe.d/sound.conf
Put in there: options snd-hda-intel model=asus
Reboot! It should work. Make sure the mic isn't muted if it didn't.
After totally searched for 2 days in Google ,at last your method works for me.
Hope you come up with such more suggestions to help, newbie like me to feel comfortable with the Linux world.
Thanks A lot...
Have a Great Day ..