06-14 00:21:30.398: ERROR/AndroidRuntime(332): Caused by: java.lang.RuntimeException: Your content must have a TabHost whose id attribute is 'android.R.id.tabhost'

what it means? I've already given the id for tabhost.And I can see the id in R.java.

Here is the .xml:

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:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="5dp"
TabWidget
android:id="@+id/tabs"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
FrameLayout
android:id="@+id/tabcontent"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="5dp"
LinearLayout
TabHost