wierd problem with array !!

[asmith]

i've got a  $_POST[john] which is an array (containing the values of a multiple select box)

$_POST[john] = array("1" ,"2" , "3" )

 

 

$fruit = array ("1" => "apple" ,"2" => "orange" , "3" => "banana" )

 

for some reasons i had to do something like this ,

 

$a = array_rand($_POST[john]);

$b = $_POST[john][$a];

 

 

echo $fruit[$b];

 

all the things run fine, no problem.

when the user click on the submit button,  $_POST[john] will be saved in a session. in the other page, there's a back button, which will redirect to this page. (IT WILL PUT THE SESSION VALUE INTO THE $_POST[john] AGAIN)

 

here comes the problem , when i click on the back button, there is no echo from $fruit[$b] ! 2 times of the 3 ! sometimes it shows "apple" which means it has been 1 , but when it choses the 2 or 3 , it dosn't show orange and banana.

what is this wierd problem  ? why one value of the array works ?

 

(i have echoed and print_r of all the  $_POST[john], $fruit , $a , $b  when i click the back button ,all shows the values, but i don't know why only this line : $fruit[$b] works 1 in 3 times !! )

 

 

 

[Lumio]

Maybe it only shows you the cached page.

[rajivgonsalves]

Yes, the back button of the browser will show you the cache page instead of the new one.

[asmith]

nono , the back button is mine,

 

<input type="submit" value="back" name="back">

 

 

if have , if isset($_POST[back])

then put all sessions variables to $_POST[...]  , then load the fist page again  ,

i said all the things run fine except this array.