动态地将值插入两个不同的数据库

I am trying to insert two values into my table using SQL: The members ID and the centre they attend. The centre table takes the Centre ID and the Members ID and links them together.

The problem is i am trying to do this via php when I add a new member (so while creating the member ID). The idea is that using the form you create the member (and an ID will be created) and add it to the members table then at the same time you insert the centre (integer) and that members ID into the Centre table

PK (auto Int)                (Linked to the members table)
CentreID         CAddress          memberID
  13                10                 1
  14                11                 2
  15                12                 3

I hope that makes some sense. I am having some trouble explaining it as i cant quite get my head around how you would do this either.

Here is a picture of my interface which is supposed to perform the operation.

Insert into Center table then use mysql_last inert id which you can use as hidden field in the next form and then save at the time of post.