hello guys, i wanna unlock my iphone like all of you, but im stuck in this step, when i start ibrickr it says that i need to free my iphone, then i click to get to the next step but i got this message saying:

Download the iPhone firmware
Looks like you need to download the iPhone firmware. Fire up iTunes with your iPhone plugged in, and hit the Restore button. Once the download starts, unplug your iPhone. When the download finishes, click away the error message in iTunes, and close iTunes. Plug your iPhone back in, and click Check again.

im stuck there, i have the firmware in itunes, what i did: i deleted the firmware and downloaded again, but didnt work, i dont know whats happening? anyone help please? what can i do? im desperate to unlock my iphone, thanks in advance!