How to set a default network connection in FC15

[Abu Attar Musharih]

Dear List,

I connect to the internet via wireless. There are two available
connections, the first one  is set up  by myself (insert IP etc), the
other  is automatically found by the network manager.

The problem is, the network manager sometimes changes the connection
to the automatically found one and creates problem as it needs proxy.

I want to make the connection which I set as a default so the manager
can not change it automatically.
I clicked the network icon next to the battery and schrolled down to
newtwork setting but could not find the way.
Any pointers?
Thanks in advance.

AA
> Linux localhost.localdomain 2.6.38.7-30.fc15.i686 #1 SMP Fri May 27 06:02:17 UTC 2011 i686 i686 i386 GNU/Linux