Word cannot re-establish a DDE connection to excel to copmplete the current
task

I have been using mail merge for a while now, word doc, excel spreadsheet,
and every now and again this message comes up, I dont understand how it
works, but can anyone give me the steps to re-establish the connection. Up
to this point I have muddled my way thru - but this time I cant get it to
reconnect.

Thanks!