“我有急事找他”用英语怎么说？

  It's urgent. Could I have his mobile phone number? 我有急事找他，可以告诉我他的手机号码吗？ It's nothing urgent. Thank you! 没什么要紧事，谢谢你！ Please ask him to call me back. 请他有空的时候回我电话。