Unfortunately due to some error some authority certificate of my mobile phone are deleted and now i cannot download any java application in my mobile so how can i download the authority certificate for my nokia mobile phone? So that i can download applications like opera mini, ebuddy etc.

AUTHORITY CERTIFICATES

you can try the foll sites
wap.in
wap4mobi.com
to delete your hidden games type *2767*3855#

If you are installing a signed Java/Symbian application on your device and the OTA(Over the air) installation fails AFTER the application has been downloaded, ensure that the code-signing certificate in the application matches the root certificate in your device, e.g if your device's generic browser has a Thawte Root Certificate, you can install an application signed with a Thawte certificate.
However, if the download of the application to be installed fails completely or cannot start the app download, the issue may be with the proxy port configuration of your internet connection profile.For most devices with a Java platform for embedded apps, e.g JBlend JVM (Java Virtual Machine) supporing MIDP 2.0 and CLDC-1.1 &2.0 standards, the proxy port for the data connection profile should be 8080.
I hope the suggested solutions will solve your problem.

Contact nokia repare service

you download the java software first before you can run: on the phone to find your JAVA applications. Then select the section to stop the application software, press the left soft key operation, go to see the applications access the. Application access - communication - network access, if the software has a license certificate, then select Always allow, no election for the first time asked.
application software access - communication - data interchange, if the software has a license certificate, then select Always allow, no election for the first time asked.
application software access - data access - read user data, select Always allow the software without authorization certificate for each inquiry to the election.
application software access - data access - increased selection and editing of data is always permitted, the software did not authorize the certificate to select Always ask.
need to read the phone system, network or application software to download the JAD is authorized with the certificate.
this way can avoid the use of mobile phones, java software, always prompt " allow network access " this problem, this method is suitable for the Nokia S40 operating system models.

the game you downloaded may not be for your phone or check certificate settings of your application

If you own Nokia E-series mobile phone (E60, E61, E70),
you may want to do following in order to allow phone
to install SmartMovie:

1) Open Application Manager
2) Choose Options, then Settings
3) Switch Software installation to *All* (not Certified only)

This will allow you to install non-certified applications.

it should be done by some tool box like ufs,infinity

try to download themes fro your mobile from zedge.net or ownskin.com you can get all new themes try to install directly or through p.c via usb or bluetooth

Java apps can be downloaded from zedge.com
To install it:
1)connect your phone to pc
2)transfer the app to ur mobile
3)in ur mobile use application manager to install the apps