startSearch not working

I have the following code in onSearchRequest

public boolean onSearchRequested() {

    startSearch(开发者_开发问答"HI", false,null,true);

    return true;
}

This is working bt uses default google search. If I use startSearch("HI", false,null,false); then search dialog doesn't open... Any reason for that?

This is the manifest file

<activity android:name=".search"
              android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
        <meta-data android:name="android.app.default_searchable"
               android:value=".SearchableActivity" />
    </activity>

    <activity android:name=".SearchableActivity"
              android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.SEARCH" />
    </intent-filter>
    <meta-data android:name="android.app.searchable"
               android:resource="@xml/searchable"/>
</activity>

AFAIK, you need to add search service in the AndroidManifest. Check http://developer.android.com/guide/topics/search/search-dialog.html for more information.