title: Error:(24, 13) Failed to resolve: com.android.support:appcompat-v7:20
body: <p>I am new to Android,i installed Android Studio <strong>1.4.1</strong> ,i am getting following errors.how may i resolve these error?</p>
  
  <p><strong>Gradle Sync</strong></p>
  
  <pre><code>Error:(24, 13) Failed to resolve: com.android.support:appcompat-v7:20.+
  &lt;a href="install.m2.repo"&gt;Install Repository and sync project&lt;/a&gt;&lt;br&gt;&lt;a href="openFile:C:/Users/Admin/AndroidStudioProjects/MyFirstApp/app/build.gradle"&gt;Show in File&lt;/a&gt;&lt;br&gt;&lt;a href="open.dependency.in.project.structure"&gt;Show in Project Structure dialog&lt;/a&gt;  
  </code></pre>
  
  <p><strong>Gradle Build</strong></p>
  
  <pre><code>Error:A problem occurred configuring project ':app'.
  &gt; Could not resolve all dependencies for configuration ':app:_debugCompile'.
     &gt; Could not find any matches for com.android.support:appcompat-v7:20.+ as no versions of com.android.support:appcompat-v7 are available.
       Searched in the following locations:
           https://jcenter.bintray.com/com/android/support/appcompat-v7/maven-metadata.xml
           https://jcenter.bintray.com/com/android/support/appcompat-v7/
       Required by:
           MyFirstApp:app:unspecified
  </code></pre>
  
  <p><strong>Build.gradle</strong></p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
      compileSdkVersion 20
      buildToolsVersion "20.0.0"
  
      defaultConfig {
          applicationId "com.example.admin.myfirstapp"
          minSdkVersion 15
          targetSdkVersion 20
          versionCode 1
          versionName "1.0"
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
      testCompile 'junit:junit:4.12'
      compile 'com.android.support:appcompat-v7:20.+'
  }
  </code></pre>