virtualbox.org

I install centos Linux 7 in my mac book. But when I select language of centos, the mouse is lock, I cannot confirm ok to continue installation. There is a scroll bar, but I cannot click and drag. Could somebody know how to solve this problem?
My virtual box appears the message as below:
The virtual machine reports that the guest is does not support mouse pointer integration in the current video mode. You need to capture the mouse(by clicking over fm

I had solve this problem by click left command.