Dealing with customers always has the potential to go south. I used to work a drug store chain and was a new cashier, it was my first month or so. It was busy and I went to open a new lane, looked behind me at the next register and asked the next cusotmer in line to come over, well the person three customers back came right away. I told her: I'm sorry I need the next person in line, you were three back and leaned back to get the other customer. The lady in fornt me threw stuff down and demanded to be checked out. I looked at her said the customers at the front get checked out first and she asked why. I told her because they had been waiting longer than her. She asked how I could possible know they had been waiting in line longer than her. I said becasue they are in front of you in line, they got there before you. She started screaming at me calling me names still demandintg to be checked out. The other customers saw me geting frazzled and upset and said to just go ahead and check her out. I was almost done when the floor manager showed up and asked what was going on. I explained, with support from the customers from the other line, what had happened. My manager sent me upstairs to calm down and relax and she finished the transaction. She later came upstairs and told me I handled it just fine and none of it was my fault. Enentually I ended up being one of the Customer Service Managers at that store, but my beginning left a lot to be desired.