Hp Notebook ztpavilionzt1130,,Mic problem!!!

Hi,
I have Hp Notebook ztpavilionzt1130, and winxp OS.I have problem with internal microphone, it is not working, Anyone can suggest where can be the problem , I have checked in sound setting , the mic is not muted.
If internal mic is not working is there any other way that i can use microphone on laptop (externally), please help
Thanks
Koreno

Did you try looking here ?

Troubleshooting Audio/Video problems in zt1130

I have a ze5400, and it doesn't HAVE an internal microphone. There are two jacks on the right edge that are headphone and microphone.