Mouse Scroll Wheel

Hi,

I have an really old version of CorelDRAW 7 Select Edition which I bought years ago which I still find really useful.  The problem I have is the scroll wheel on my mouse doesn't work.  How do I get it to operate?  

I have moved this program from computer to computer as I have upgraded my hardware over time and it has never worked, except mysteriously on one machine in the dim and distant past, so it must be possible, but how?

Thanks in advance

Peter