Cant Type Message in Outlook

[Mark]

Some time I am able to type in outlook and other time it
will not work. I dont know that is going on or if there
is something that I do to bring it on. I was answering
my email this morning and when I got to the last one i
was not able to type. Every key stroke it would ding at
me. It did this to me before and the problem just went
away. I have tried to reboot my computer and that didnt
work. I have no idea.

Thank You

Mark