本程序的功能是判断文件是否被修改。运行程序，编辑完窗体中的文件信息后，在退出程序时会弹出提示对话框信息，单击“是”或“否”按钮来决定编辑的信息是否保存，单击“取消”按钮则退出程序操作-This procedure s function is to determine whether a document is modified. Run programs, edit documents in the form information, withdraw from the program in the prompt dialog box will pop up message, click　yes　or　No　button to edit the information to decide whether to preserve, click　Cancel　button while withdraw from the process operation