Can I file a civil suit against a clothing store whose employee demanded to search my purse?

I went shopping with my daughter. We were buying her some new clothes. A couple times we had went into the dressing room and she tried on clothes. When we were done shopping we went to register to pay and a young man came over to the register and said excuse me but our policy says only one person in the dressing room at a time and our policy also says that I have the right to search your purse please I said excuse me and he said actually "ma'am, it's the law". So I need to see your purse, I handed him my purse and asked for a supervisor and was told there wasn't one there at the time. He handed me back my purse and I said I don't see anywhere that it says that there is only one person in the dressing room at a time. Nor do I see your policies posted around. He said it's their policy and I've already asked my supervisor and it is the law that I can search your purse and I said I'm sorry but your wrong. At that point i asked the other employee that was checking me out to just finish the transaction so I could leave. Once outside a woman approached me with a young girl with her and said she heard the whole thing and she too thought it was completely wrong what he did an that I should definitely talk to someone.