Link error for IOS on MAC OSX
<p>When I link a program for IOS on MAC OSX 10.7, the follow error message is displayed.</p>

<pre><code>Ld build_iOS1/bin/osgViewerIPhoned.app/osgViewerIPhoned normal i386
    cd /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph
    setenv MACOSX_DEPLOYMENT_TARGET 10.6
    setenv PATH "/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
    /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/clang++ -arch i386 -isysroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk -L/Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/bin -F/Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/bin -filelist /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/examples/osgviewerIPhone/OpenSceneGraph.build/Debug-iphonesimulator/example_osgViewerIPhone.build/Objects-normal/i386/osgViewerIPhoned.LinkFileList -mmacosx-version-min=10.6 -Xlinker -objc_abi_version -Xlinker 2 -framework QuartzCore -framework Foundation -framework OpenGLES -framework UIKit -Wl,-search_paths_first -Wl,-headerpad_max_install_names /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libOpenThreadsd.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgd.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgDBd.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgUtild.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgGAd.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgViewerd.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgTextd.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgdb_osgd.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgdb_freetyped.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgdb_imageiod.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgGAd.a -framework Cocoa /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgTextd.a /Users/sun/Desktop/OpenSceneGraph/3rdParty_IPhone/lib/libFreeType_iphone_universal.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgDBd.a /usr/lib/libz.dylib /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgUtild.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libosgd.a /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/lib/libOpenThreadsd.a -lpthread /usr/lib/libm.dylib /usr/lib/libdl.dylib -framework OpenGL -framework Accelerate -Xlinker -no_implicit_dylibs -D__IPHONE_OS_VERSION_MIN_REQUIRED=50000 -o /Users/sun/Desktop/OpenSceneGraph/OpenSceneGraph/build_iOS1/bin/osgViewerIPhoned.app/osgViewerIPhoned

ld: framework not found Cocoa
Command /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/clang++ failed with exit code 1ld: framework not found Cocoa


Command /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/clang++ failed with exit code 1
</code></pre>

<p>Could anyone help me?</p>
