简单的练习程序,这个程序简单易学。是我第一次做的程序。我只想下载一部分有用的程序来完成我的设计，希望不要有这么麻烦的注册-it is a practice programme,and it is very simple.i did it the first time and i don t even know a lot about its function.but i just want to download some files to complish my work