XCode Compiler Error: ld: library not found for -loauth

I'm trying to use the Twitter libraries and after adding liboauth.a and adding oauthconsumeriphonelib to my header search path, I'm now down to 1 compilation error, which I can't seem to get rid of.

ld: library not found for -loauth
Command /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/gcc-4.2 failed with exit code 1

Anyone know what could be causing this?

Continuing to What Robin suggested You also need to set the Library Search Path. Right Click the Target File and Choose -- Get Info else you can also get the same by choosing Edit Actice Target Under the Project Tab in XCode. Look for Library Search Path and add this "$(SRCROOT)/Twitter+OAuth/SAOAuthTwitterEngine" Where Twitter+OAuth/SAOAuthTwitterEngine is the directory path for Twitter Library in project folder. I hope this will fix the problem.