表头固定，根据表格高度让table里的内容隔一段时间循环滚动，设置表格高度为td的整数倍，可自己设置停顿时间简单方便-Header is fixed, according to the table height so that table contents from time to time in the cycle of rolling, set the table height is an integer multiple of td can set up their own simple pause time