Help pls.. I'm new to this AT&T root thing and I bricked my phone..

I was trying to downgrade through Odin 3.10 to 4.4.4.. now i'm stuck with a error
<ID:0/003> Odin engine v(ID:3.1005)..
<ID:0/003> File analysis..
<ID:0/003> SetupConnection..
<ID:0/003> Initialzation..
<ID:0/003> Set PIT file..
<ID:0/003> DO NOT TURN OFF TARGET!!
<ID:0/003> Get PIT for mapping..
<ID:0/003> Firmware update start..
<ID:0/003> SingleDownload.
<ID:0/003> aboot.mbn
<ID:0/003> NAND Write Start!!
<ID:0/003> sbl1.mbn
<ID:0/003> rpm.mbn
<ID:0/003> FAIL! (Auth)
<ID:0/003>
<ID:0/003> Complete(Write) operation failed.
<OSM> All threads completed. (succeed 0 / failed 1)
Some one please help me if there is any way to fix this problem..