When i formate my mobile nokia5800i music express by entring number *#7370# then it takes password and i entre password 12345 but it says that wrong password .plz help me kindfully.

The password might not be what was set before, if you dont remember setting the password try entering 00000.
If that doesnt help do a hard reset, but before that you should backup your phone memory to pc or memory card.

you can do the hard reset by
1) Switch Off mobile
2) Press Green+Red+Camera Keys together & press Power Button & hold those key untill you get Nokia Handshaking Screen.
but that time you will loose all the phone memory data.
It will clear that password & the Counter will automatically set to Zero,
the default code will be 12345.

If this doesnt work you will have to take it to Nokia Care.

It is wrong password for 5800 00000 is correct password or when u security locked ur phone then type that password which u used in ur phone it format the ph.