How can I select from drop-down list and jumping to selected subform?

I using LC Designer ES2 vers 9. Developing XDP. How can I Select from a drop-down list the appropriate selected subform (jumping to the selected subform on the page)?

drop-down list...A (jump to subform1)

                         B (jump to subform2)

                         C (jump to subform3)

subform1

     .

     .

     .

subform2

     .

     .    

     .

subform3

     .

     .

     .

....end of form