Admob implementation Error

Question

I got a Problem with implementing Admob into an App.

This is my main.xml:

Answer 1

if you use AndroidStudio and Gradle, you must also update the build.gradle file like this:

android {
    compileSdkVersion 17
    buildToolsVersion "18.0.1"

    defaultConfig {
        minSdkVersion 3
        targetSdkVersion 17
    }
...