Compile Error when add build file in android studio.

[Former user]

my build file is:

dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) compile 'com.android.support:appcompat-v7:21.0.3'

compile project(':HoloGraphLibrary')

}

but i get this error: Error:(26, 0) Project with path ':HoloGraphLibrary' could not be found in project ':app'.