1.
intro
2.
document write
3.
alert
4.
variable
5.
variable-rule
6.
global local variable
7.
operator
8.
if
9.
switch
10.
while
11.
for
12.
continue and break
13.
confirm
14.
making js function
15.
return
16.
recursive function
17.
object
18.
creating event
