InfoPath Dev

Is it possible to set rules on a multiple selection list box that are based on a drop down control. Example if I select america on dropdown it should the countries related to america on the multiple selection list box.   Thank you, Sneha  

hi  Can any body help me I am facing one issues related to multiple selection list box. Is it possible to set rules on a multiple selection list box that are dependent on a drop down control? Example: if in dropdown I select America then on multiple selection list box countries under america should be displayed.  thak you in advance