iRule to insert header ntCoent-Length based in URI

Hi Hamish, thanks a lot for your answer, the reason why I must include that header is because I am migrating this configuration from a Citrix netscaler, which balances to a legacy application server, I offered to enable the chunking within the http profile, , I am not sure why they need this header within the application, but unfortunatelly I must meet the requierement exactly as they asked. Thanks a lot!!!