As we did for USERNAME in the previous step, set the value as required on the validation TAB, and set the control up to display validation error messages in an error messagecontrol.
In this case, you want to control the display of each message individually, based on the test specified by its associated Schematron assert or report.
在这个示例中，希望根据相关schematron断言或报告指定的测试来分别控制每个消息的显示。
3
The first line will pop up a message on the control nodes' display (if X Window System is active), letting the user know that the laptop is inactive and needs to be powered down.
第一行将在控制节点的界面上弹出消息（如果 X Window System 处于活动状态），从而让用户知道笔记本处于非活动状态并且需要关闭。