Java Card

Hi
I am using ACOS CCID SDK , SMART CARD READER ACR 38 Reader, Acos3 Card .I created a user file(DD 11) with Write Command
80 D2 00 00 07 08 01 00 00 DD 11 00
it is succesful status
After that i selected that file
80 A4 00 00 02 DD 11
Succesful Status
After sucessful status i write data into that record as 01 02 03 04 05 06 07 08
80 D2 00 00 08 01 02 03 04 05 06 07 08
while in reading the data with the Read Command

i am getting this SCardTransmit Error :(0000007A) Unknown Error

Can one suggest me how to rectify error

and just i am working with PCSC Tool

I want to write code Which Methods are Required to Implement Simple Application in Java Card in ACOS3 sdk

Cheers,

Thanks for Concern
Naveen.C