Normally Samsung android phones are so secure to flash. but you are unlucky and got your phone bricked during flashing,rooting or upgrading.
Here is a good news for You – A developer come up with a software called one-click unbrick for Samsung android phones. this small utility uses ODIN to repair our Samsung phones. almost all Samsung phones with android éclair and above can be repair with this tool (few exceptions – it is working on some Android 1.5 too)
one-click unbrick tool works on windows , Linux and mac also. it have some bugs in windows version but both Linux and mac working fine. don’t get worried about windows version if you are a window user. developers are continuously working on windows version for its stability
REQUIREMENTS TO UNBRICK YOUR PHONE
> First install java on your pc if you haven’t java go to Java site
and install it.
> download one-click Unbrick tool
(if you don't have one, click the link and click download folder then install)
FOLLOW THESE INSTRUCTIONS CAREFULLY
1. Right-click on the One-Click.jar file, select “Extract to OneClick”.
2. Copy ‘OneClick.jar’ file and paste it into the ‘OneClick\heimdalloneclick\resources\HeimdallPacka ge’ folder.
3. Right-click on ‘oneclickloader.exe’ file and choose ‘Run as Administrator’.
4. Proceed with the installation of Heimdall.
5. After the installation is complete, you will see the the One-Click UnBrick interface.
6. Connect the phone to computer via USB and click on “unsoft brick” button to recover your bricked Samsung android phone.
7. Hope for the best. Goodluck
Source -- Androidflip