Ns2 nodes would not make http request concurrently

I wrote an ns2 script to run concurrent HTTP requests from 40 nodes out of 80 nodes. However, the simulation showed one node, rather than 40 nodes, make requests to the HTTP server. Could someone please clarify what might be wrong with the code. Thank you for your time, everyone. The links to the code screenshots are provided below:

1. The loop statement: http://ift.tt/1J1emFd

2. Ns2 HTTP configuration representing client(nodes) to cache, cache to HTTP server: http://ift.tt/1EtXAir