4.
if
(
isset
(
$_POST
[
'action'
]
&&
$_POST
[
'action'
]==
'submit'
)){
5.
if
(
$_SESSION
[
'num'
]
==
0
){
6. echo
'<a href="'
.
$_SERVER
[
'PHP_SELF'
].
'">'
请再次尝试</
a
>;
'
7.
$_SESSION['
num
'] = 1;
8. }else{
9.
echo '
您已经提交过了,请不要重复提交
';
10. }
11. }
12. ?>