Xcode error

i whas makin a xcode program and found this error

CodeSign error: code signing is required for product type 'Application' in SDK 'Device - iPhone OS 3.1.2'

on the simulator it works good but not whit the others!
what do i need to do!

Take a look at:

Issue 18 - cocoahttpserver - CodeSign error: Code signing required for the product type 'Application' in SDK 'Device - iPhone 3.0' - Project Hosting on Google Code

Although it talks about iPhone OS 3.0, I think the material in the fix is probably still relevant.

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