Should you experience any difficult,do not hesitate to contact one of my staff members.
一、句子使用语气的解释：
这是个“虚拟条件句 + 祈使句”的复合句
1.条件虚拟语气在这里是一种客套语,即不强求对方非得接受 .
2.祈使句也是一种客气,表示请求
二、关于条件虚拟的倒装：
条件虚拟句常可以用倒装语序表示.倒装时只要省去 if 再把助动词或情态动词提前放在主语前即可,如本句：
提前 should：Should you experience any difficult = If you should experience any difficult,假如你们觉得有什么难题的话,
再如：
* 提前 were：Were you to be here tomorrow,...= if you were to be here tomorrow,...假如你明天会在这里的话,...
* 提前 did：Did he come now,...= If he came now,...如果他现在就来的话,...
* 提前 had：Had the students finished their homework on time,...= If the students had finished their homework on time,...如果学生原来就按时完成了作业的话,...