How to avoid switching frame when switching buffer?

[Wenbo CAI]

Hello guys,

I am using emacs 23.3.1 on Ubuntu 12.04.
I have 2 frames open.  Now I am on frame A.  When I switch to a buffer which is 
visible on frame B, then the frame is switched - frame B has the focus.  

I feel not comfortable with this behavior (maybe because both frames are full 
screen).  I prefer the frame is not switched - just switch the buffer to frame 
A.

Is there any way to avoid frame switching when do buffer switch?
Thanks in advance.

Btw, I am using ido-switch-buffer.

Regards,
Wenbo