Help on automatic allocation

Hi all

I have attached a dummy version of my report with name changes

I have produced a spreadsheet which the main function is to automatically allocate a new account manager to an account but this cannot be the last account manager, it has to be someone different.

I have set the spreadsheet up using formulas to randomly select a person from the individual teams - this all works perfectly.

What I am having trouble with is making it recognise the last account manager so when it radomly selects a new person, it is a different person to the last account manager.

Is there a formula I can add in to do this last bit?

would REALLY appreciate any help!!