Partitioning <Grid> tag to Position RadControls

[Maurice]

I notice that you can create columns and rows in the <Grid>.  I want to divide the grid in half and associate some controls with Row 0 and some with Row 1. I know there is a RowSpan as well which i usually set to 1.

The problem is that I often can't get my controls to line  up in the right rows. What properties do i need to look at?

<Grid x:Name="LayoutRoot" >
<Grid x:Name="TopGrid" >

Controls

</Grid> 
------------------------------------------------------  Row Division

<Grid x:Name="BottomGrid" >

Controls

</Grid> 


</Grid> 
Thanks!