Can not delete received packet in the receiving end [Desperately searching help !!!]

[Abir]

Dear

greetings.

i am trying to do my ALOHA simulation for large number of user. i successfully dispose packet at the sender site but in the receiver i tried to delete the received packet but the system hang on and create errors.

i desperately need help. i could not understand my errors.

The full code is available in here 

Thanks for read the post.