I have 2 xamcomboeditors in my Grid and selected item of first should pass as a string parameter to ObjectDataProvider of second. How to bind the selected item of first to method parameter of object data provider of second

<ObjectDataProvider x:Key="dbNames" MethodName="GetName" ObjectType="{x:Type myApp:NameList}" >
<ObjectDataProvider.MethodParameters>
<x:Static Member="sys:String.Empty" />
</ObjectDataProvider.MethodParameters>
</ObjectDataProvider>

<ObjectDataProvider x:Key="dbSNames" MethodName="GetSName" ObjectType="{x:Type myApp:SNameList}" >
</ObjectDataProvider>

<ig:XamComboEditor x:Name="cmbBrowse" Height="20" Width="100" Padding="3,2" Margin="10 0 0 0"
IsEditable="True" AllowFiltering="True" AutoComplete="True" 
OpenDropDownOnTyping="False" VerticalAlignment="Center" HorizontalAlignment="Left" Grid.Row="1"
ItemsSource="{Binding Source={StaticResource dbSNames}}">
</ig:XamComboEditor>
<ig:XamComboEditor Name="cmbName" Height="20" Width="180" Padding="3,2"
AllowMultipleSelection="False" IsEditable="False" Grid.Row="2"
ItemsSource="{Binding Source={StaticResource dbNames}}" Margin="0 0 300 0">
</ig:XamComboEditor>

Code Behind:

public class NameList
{
public ObservableCollection<TypeList> GeName(string name)
{
if (!string.IsNullOrEmpty(servername))
{
ObservableCollection<string> lst = Program.GetCollectionFromDataset(Program.GetName(name));
if (lst == null)
return new ObservableCollection<TypeList>();
else
{
ObservableCollection<TypeList> cst = new ObservableCollection<TypeList>();
foreach (string s in lst)
{
cst.Add(new TypeList(s));
}
return cst;
}
}
else
return new ObservableCollection<TypeList>();
}
}

public class SNameList
{
public ObservableCollection<TypeList> GetSName()
{
ObservableCollection<string> lst = Program.GetCollectionFromDataset(Program.GetSName());
if (lst == null)
return new ObservableCollection<TypeList>();
else
{
ObservableCollection<TypeList> cst = new ObservableCollection<TypeList>();
foreach (string s in lst)
{
cst.Add(new TypeList(s));
}
return cst;
}
}
}
#endregion

public class TypeList
{
public string fieldOptions { get; set; }
public TypeList()
{
fieldOptions = null;
}
public TypeList(string a)
{
fieldOptions = a;
}
}