I'm trying to put a menu on my application, but when I put a menu tag in my xml like this:

```
<menu
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" >
    <item
        android:id="@+id/item1"
        android:title="Item 1">
    </item><item
        android:id="@+id/item2"
        android:title="Item 1">
    </item>
    <item
        android:id="@+id/item3"
        android:title="Item 1">
    </item>
</menu>

```

I get this error message when I go on the graphical layout.

```
java.lang.ClassCastException
Exception details are logged in Window > Show View > Error Log
The following classes could not be found:
- item (Fix Build Path, Edit XML)
- menu (Fix Build Path, Edit XML)

```

Anyone know why?