how to intigrate hdfc paymentgetway using asp.net

Question

Hi Friends,
        i have the problem to integrate hdfc paymentgetway...
i done some steps then finally i get this error.

Transaction Response
Transaction Status																																			Transaction Failed
Merchant Reference No:[TRACK_ID]																																			11188
Transaction Amount																																			1.00
Error Description																																			!ERROR!-GW00456-Invalid TranPortal ID.

can any one give me u r valuable ideas how to do...