marquee for TextView not working

I added marquee tag but it not working.... here is my coding..any one check and tell..why it is not working...

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill开发者_StackOverflow_parent"
    >
    <TextView 
    android:id="@+id/txt3" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content"
    android:singleLine="true" 
    android:ellipsize="marquee"
    android:marqueeRepeatLimit="marquee_forever"
    android:textColor="#00FF00"
    android:text="News Blog"
    />
<TextView 
    android:id="@+id/txt1" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="Artical topic"
    />
     <EditText android:id="@+id/txtName1"
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content"
        />
        <TextView  
        android:id="@+id/txt2"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="Artical"
    />
    <EditText android:id="@+id/txtName2"
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content"
        />
     <Button
        android:id="@+id/submit"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_marginLeft="dip"
        android:text="Submit" />
    <Button
        android:id="@+id/Cancel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@id/submit"
        android:layout_alignTop="@id/submit"
        android:text="Cancel" />

</LinearLayout>

A marquee starts when a TextView becomes either focused or selected.

You can force it to start by calling

tv.setSelected(true);

if you get any problem then put comment.