ViewPager in android is taking full screen?

In my xml file I have a Linear layout that has a ViewPager for showing images and another Linear layout that contains previous and Next buttons for selecting images.My xml looks like this:

 <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <android.support.v4.view.ViewPager
            android:id="@+id/pager"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:orientation="horizontal" >

            <Button
                android:id="@+id/goto_first"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="first" >
            </Button>

            <Button
                android:id="@+id/goto_last"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="last" >
            </Button>
        </LinearLayout>

    </LinearLayout>

My problem is that the ViewPager is taking full screen and the Linearlayout with previous next buttons is not showing up because there is no space left to draw this LinearLayout.

I am using Fragments to populate ViewPager with views.The xml file for the fragment view that goes into ViewPager is:

<ImageView
    android:id="@+id/ItemImage"
    android:layout_width="320dp"
    android:layout_height="180dp" />

<TextView
    android:id="@+id/ItemText"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="left|bottom"