Modifying the master data displayed as header on details page...

Hi,

I have a master-details relationship, with 'show master data on details list page' enabled.

The data displayed from the master table is a straight copy of the fields in the master table - I would like to be able to only show some data from the master table, not all of it, and alter the layout.

I have looked, and googled it but can find no reference to how to do this.

Has anyone got any pointers I could use?

Many thanks
DAvid