telerik combobox Selected index changing

Question

 I have a radcombobox outside the grid,
and one combo inside the grid I want to bind combobox box which is inside the grid based on selection of combobox outside.
 
urgent help required..!!! I have a radcombobox outside the grid,
and one combo inside the grid I want to bind combobox box which is inside the grid based on selection of combobox outside.
 
urgent help required..!!!