I'm new to WPF. I've just been trying to put a menu bar and a grid object in a window, but I always get the exception that I am trying to set a content property more than once. I can't figure out how to put a menu along with other elements in the window.

<Window x:Class="WpfApplication1.MainWindow"
    Title="Eliptical Button">
        <Menu IsMainMenu="True">
            <MenuItem Header="File">
                <MenuItem Header="New"/>
                <MenuItem Header="Open"/>
                <MenuItem Header="Save"/>
                <MenuItem Header="Save As..."/>
                <MenuItem Header="Exit"/>
            <MenuItem Header="Edit"/>
Can someone please help me to get this right? Thanks.