ListView List posiiton is over the EditText

I have an EditText object, and a ListView that is populated with items when text is entered into the EditText object.

Currently, when I type text into the EditText, the ListView is displayed, but is over top of the EditText, such that I cannot enter in any more data.

How can I display the ListView under the EditText object?

Here is my Layout code:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="horizontal"
    android:padding="5dip">
    <FrameLayout
        android:id="@+id/mapWithOverlay"
        android:layout_width="fill_parent"
        android:layout_height="match_parent"
        android:background="#ffffff"
        android:layout_below="@+id/thumbnail" />
    <ListView
        android:id="@+id/List"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />
    <EditText
        android:id="@+id/inputSearch"
        android:layout_width="281.5dp"
        android:layout_height="45dp"
        android:hint="Find..."
        android:layout_marginBottom="15.2dp"
        android:layout_marginTop="8.5dp"
        android:layout_marginLeft="8.5dp" />
</RelativeLayout>

Thanks in advance