How do I autocreate Foreign Key indexes?

Hi, I have a Logical data model in which I create two Entities. I draw a Relationship between the two Entities to propogate the Foreign Key into the child Entity. I then use the "Compare and Merge Utility" to generate a Physical data model. When I view the "Indexes" on the child Table I expected to see a Foreign Key index but there is only the Primary Key index. Is there an option/setting I'm missing? Any help or guidance would be appreciated. Just to add that when you "Generate Physical Model" it gives you an option to "Generate Physical Indexes" on "Foreign Keys" which is fine. But how do you do this when you have an existing Physical model you are compare and merging into? Help! Regards, Pete