Problem with Mozilla...Chrome & IE is working fine

I have one set Password page,which open in pop up..

Structure is like that-
1-TextBox for UserName
2-TextBox For Passsword
3-Textbox for Confirm Password.
4-Two Submit button(For Add & For Update)

Problem is that whenever new user is created & when we go to set password page to set there username and password.

Mozilla comes with some dummy data in Username & Password field. Otherhand,Chorme & Ie is working well.

Kindly Help to sort out this issue.

I used-

Thanks