echo和@的用法：
http://blog.csdn.net/stpeace/article/details/9039685
例子：
test.bat
@echo off
@echo 1
echo 2
echo 3
@echo on
@echo 4
echo 5
echo 6
echo off
@echo 7
echo 8
echo on
@echo 9
echo 10
pause
执行结果：
1
2
3
4
C:\Users\lujunhua\Desktop>echo 5
5
C:\Users\lujunhua\Desktop>echo 6
6
C:\Users\lujunhua\Desktop>echo off
7
8
9
C:\Users\lujunhua\Desktop>echo 10
10
C:\Users\lujunhua\Desktop>pause
请按任意键继续. . .