How to get phone screen layouts in graphical layout of activity_main.xml ? I see only tab layouts

Hi I'm a beginer in android app development. I can't see how to get a portrait layout in the graphical layout section,only tab layouts are present. Here is how the it looks.

see image

Here is the activity_main.xml file :

<RelativeLayout xmlns:android="http://ift.tt/nIICcg"
xmlns:tools="http://ift.tt/LrGmb4"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#00BBFF"
android:gravity="center"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.mylocationwiki.MainActivity" ></RelativeLayout>

In the manifest file I have changed the orientation by adding android:screenOrientation="portrait"

Here is the complete file:

    <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://ift.tt/nIICcg"
    package="com.example.mylocationwiki"
    android:versionCode="1"
    android:versionName="1.0" >



    <uses-sdk
        android:minSdkVersion="11"
        android:targetSdkVersion="21" />

    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />

        <activity
            android:name="com.example.mylocationwiki.MainActivity"
            android:label="@string/app_name"
            android:screenOrientation="portrait" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Any suggestions will be very helpful. Thanks!