[Grinkl]

Hi! techers.

A:We need to regulate the system.
B:I agree that regulations are necessary but there's a promblem.
A:What is it?
B:The problem is how to regulate it.

I wanna know two things about the converastion. First, Isn't there any wrong part above? Second, isn't comma necessary before but in the first
B line like " ,but there's a problem"?

thanks in advance.

regards.