title: LinearLayouts on top of each other
body: <p>I'm must getting started with android app development.  I'm using Android Studio and working through the tutorial.  I keep having 2 elements lay on top of each other, whereas one should be below the first element.  It is probably a very noob mistake, but hey, I'm a noob and I don't know what it is.  :)  Code follows:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.design.widget.CoordinatorLayout 
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:fitsSystemWindows="true"
  android:orientation="horizontal"
  tools:context="org.kehrli.testapp.MyActivity"&gt;
  &lt;LinearLayout
      android:layout_width="match_parent"
      android:layout_height="60dp"
      android:theme="@style/AppTheme.AppBarOverlay"&gt;
      &lt;android.support.v7.widget.Toolbar
          android:id="@+id/toolbar"
          android:layout_width="match_parent"
          android:layout_height="?attr/actionBarSize"
          android:background="?attr/colorPrimaryDark"
           /&gt;
  &lt;/LinearLayout&gt;
  
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:orientation="horizontal" &gt;
  
      &lt;EditText android:id="@+id/edit_message"
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          android:layout_weight="1"
          android:hint="@string/enter_message" /&gt;
      &lt;Button
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="@string/button_send"/&gt;
  &lt;/LinearLayout&gt;
  
  &lt;android.support.design.widget.FloatingActionButton
      android:id="@+id/fab"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_gravity="bottom|end"
      android:layout_margin="@dimen/fab_margin"
      android:background="?attr/colorPrimary"
      android:src="@android:drawable/ic_dialog_email" /&gt;
  </code></pre>
  
  <p></p>
  
  <p>Can anyone see where I went wrong?</p>