Topic "Databse Mirroring" a message from MOBO

Hi there,

we are trying to configure RDM for Database Mirroring.

We enter the Mirror-Server-Hostname in the field &quotFailover Partner&quot but then RDM throws an error saying, that &quotInitial Catalog&quot also needs to be specified.
But there is no field for &quotInitial Catalog&quot and if we enter a complete SQL-Connection-String into the &quotFailover Partner&quot field, RDM wont save the information.

How does DB Mirroring work?