Ionic Lab problem with android

Basically i am working in Ubuntu.I created my application and set the platform android but i am getting

** ERROR**
Command failed with exit code 2 Error output: { [CordovaError: Failed to find ‘ANDROID_HOME’ environment variable. Try setting setting it manually. Failed to find ‘android’ command in your ‘PATH’. Try update your ‘PATH’ to include path to valid SDK directory.] name: ‘CordovaError’, message: ‘Failed to find ‘ANDROID_HOME’ environment variable. Try setting setting it manually.\nFailed to find ‘android’ command in your ‘PATH’. Try update your ‘PATH’ to include path to valid SDK directory.’, code: 0, context: undefined

Help me out…plzzzzzzzzzzz