Different detail Index order within master-detail relationship

Hi,
    I have 2 tables linked in a Master-Detail relationship using the
Mastersource/Masterfield properties of one of the table.  Whenever I try to
change the indexname property of the detail table to another index, all the
corresponding detail records disappeared. eg. I want the detail customer
table to show me a list of all customer ids for a corresponding master shop
table. The joined field in this case would be shop id.  In addition I want
the customer-ids of the particular shop id to be displayed based upon
customer-id order (but I can't seem to get it).

Thanks for any help rendered in advance!