Error: Call to undefined method CI_Input::CI_Input

[eluser]Unknown[/eluser]
Thanks, it got me abit further.

But I'm not quite there, I have php 5.3 installed. But the code is not mine, but I'm trying to convert it, and I'm abit rocky to what this is doing. I think it' supposed to change the header, but it doesn't do anything. Except the welcome script, that is working now.

Any ideas?