I want a theme for my mobile samsung c3530 . but i didn't get it . i also want to know about the file extension of mobile theme. like most of the mobile software are made in java and the file(software) extension for that file is .jar .

SOURCE: how to install themes on my samsung e250

Just type *#52828378# (aka *#JAVATEST#)
After typing this code you get the "java test" menu, where if you go to "OTA type setting" you can select the "Serial bearer OTA".
After selecting that exit the menu, and you can follow the same steps for the D500 phone.

The main code that enables/disables serial upload on the phone doesn't work (#*536963#, #*536961#, #*536962#, #*53696#), but the next code that gives the PPP menu works (#*5737425#). This second code is useless unless the first code works, therefore it's not possible to upload java apps.

1)Install Bluesoleil software for your dongle.
2)Insert the bluetooth dongle in USB port.
3)The bluesoleil software should display "BLUETOOTH STARTED" when the dongle is inserted.
4)Enable bluetooth on your phone.
5)Press F5 when the bluesoleil software is opened.
6)The bluesoleil software will start to search your mobile phone.It will hopefully detect your phone.
7)Click on "Bluetooth serial port service" on bluesoleil when your phone is selected.
8)Accept serial port service from your phone.
9)Install softick PPP and from SETTINGS,go to BLUETOOTH/SERIAL and configure your bluetooth ports.
10)Type *#52828378# on your phone.
11)Go to serial test.
12)Go to PPP UP and select bluetooth.
13)The phone may restart at this point.
14)Open samsung java uploader and add a JAD file to it.
15)Again type *#52828378# on your phone and go to Serial download.
16)Hopefully the phone should start installing the application/game.

SOURCE: how to install jar files to samsung sgh e250

this site automatically detect your handset and you can download the jar files. the website are:

www.zedge.net

Thanks.