Disable keyboard or Enter Key during a msgbox

How do I do this? I only want the user to use the mouse when one of my yes/no msgboxs comes up in the code. Some just enter through without realising.
The below lines work for a workbook, but need it to work only when the msgbox is up so the user cant press ENTER.

e.g.

Application.DataEntryMode = True
MSGBOX
Application.DataEntryMode = False

Help, this should be simple??