Checking then copying information

Hello,

I am trying to use VBA to check whether an M appears in column B and then if it does, paste the information from that row (A through to W) into another existing sheet in the workbook. I want this to be able to check the whole worksheet and then finish when it gets the the end of the information in column B.

Any ideas, I have been playing around with it for about 4 hours and have got nowhere!!!

Help me please!