I have a WPF form , in that I have a combobox, when I Scroll down the combobox using the Mouse scroll wheel -> it will scroll the page as well as scrolls the combo box. what should I do so that the mouse scroll wheel only scrolls down the combo box and not the whole page.

Here is how it looks like in xaml:
<corewpf:RapDataGridFilteredComboBoxColumn MinWidth ="60"
Header="BU ID"
HeaderStyle="{StaticResource RequiredColumnStyle}"
IsReadOnly="True"
FilterBehaviorType="Contains"
FilterMemberPath="ShortName"
FilterSecondaryMemberPath="BusinessUnitID"
Background="{StaticResource DisabledBackgroundBrush}"
TextPath="BusinessUnitID"
CodeMemberPath="BusinessUnitID"
DescriptionMemberPath="ShortName"
SelectedValuePath="ID"
DisplayMemberPath="BusinessUnitID"
SelectedValueBinding="{Binding Path=BusinessUnitEntityRID, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
ItemsSource="{Binding Path=StaticDataContext.BusinessUnits, Source={StaticResource proxy}}">
</corewpf:RapDataGridFilteredComboBoxColumn>

And the code behind for scrollviewer looks like this:
private void Main_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
svMain.ScrollToVerticalOffset(svMain.VerticalOffset - e.Delta);
}

What should I change/add so that when the combobox is selected the mouse scroll only scrolls the combo box and not both combox and the page.

Thanks