I just finished a basic Algo course on Udemy and one of the things we did at the end was code a BB Mean Reversal EA. It runs a check to see if there are any open trades with its magic number, and won't put on a new trade if it finds one. I have one question about testing it live on a demo account...if I put it on multiple charts so that I can trade multiple pairs, is the magic number check going to only let me be in one trade at a time? How can I be in multiple pairs with that magic number check? Would I need to code a separate EA for each pair and have each one with a unique magic number?