DSP page Problem

Hello everyone,
I have written a DSP page and I have used invoke statement. But when am opening it is giving the code instead of results. The code is below

Current Transactions

%invoke DSP_Example:tn_info% %loop results% %end% %end%
SENDER ID RECEIVER ID ROUTINGSTATUS
%value SENDERID% %value RECEIVERID% %value ROUTINGSTATUS%