I want to include library in android studio , but display error like below :

" failed to resolve:com.lemonlab:expandable-button-menu:1.0.0 "

How to fix this problem...

 apply plugin: 'com.android.application' android { compileSdkVersion 21 buildToolsVersion '21.1.2' defaultConfig { applicationId "ayowes.com.newecampus" minSdkVersion 15 targetSdkVersion 21 versionCode 1 versionName "1.0" } buildTypes { release { minifyEnabled false proguardFiles getDefaultProguardFile('proguard-android-ptimize.txt'), 'proguard-rules.txt' } } } dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) compile 'com.android.support:appcompat-v7:21.0.3' compile 'com.google.android.gms:play-services:6.5.87' compile 'com.lemonlab:expandable-button-menu:1.0.0' compile files('libs/pinchzoom.jar') }