The Confrontation

Ehud and Benjamin are participating in a public debate. Each one presents a question to his opponent in turn. Ehud is chosen to be the first to present a question. A "tricky question" is a question that the opponent has no answer to. A contestant who manages to ask a tricky question immediately wins the debate. The probability of each of the two contestants finding (in turn) a tricky question is exactly 1/2. Also, it is known that there is no dependence between the questions. What is the probability of Ehud winning the debate?