Add image on 3 tabs

How can I add images into tab ? Currently I'm able to move the tab to bottom but have no idea on how to change the LL Tab1, LL Tab2, LL Tab3 to icon.Am I on the right path ? Any help would be greatly appreciated.

xml code

<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/tabhost"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="vertical"
        android:padding="5dp" >


        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:padding="5dp"
            android:layout_weight="1" >

            <LinearLayout
                android:id="@+id/ll_tab1"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical" />

            <LinearLayout
                android:id="@+id/ll_tab2"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical" />

            <LinearLayout
                android:id="@+id/ll_tab3"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical" />
        </FrameLayout>
        <TabWidget
            android:id="@android:id/tabs"
            android:background="@color/light_gray"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="0"/>
    </LinearLayout>

</TabHost>

Anyone can help? Thanks a lot !