Can't set variable from $_POST

I can't set a variable from a post array.

I have a simple form with a hidden field in it: <input name="sid" type="hidden" id="sid" value="<?=$sid?>">

This hidden field gets sent off to a second file (exec.php) where I have the following code:

$sid = $_POST['sid'];

For some reason, when trying to set $sid, it gets a NULL value. For haha's, I ran the following:

foreach($_POST as $var => $value)
{
echo $var . ' : ' . $value . "<br>";
}

This provided a correct value of 1938 for sid. I've looked at this for 3 hours and can't find what is happening. I expect something extremely stupid...any thoughts?

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Here is the form on enter.php

    <form name="form1" method="post" action="exec.php">
     <input name="sid" type="hidden" id="sid" value="<? echo($sid); ?>">
     <input name="ticket_totals" type="hidden" id="ticket_totals" value="<?=$ticket_totals?>">
     <input name="emp" type="hidden" id="emp" value="<?=$emp?>">
     <input name="submit" type="submit" id="submit" value="Submit">
     <input type="submit" name="submit" id="submit" value="Close">
    </form>

Here is the POST output on exec.php: type : Other ticket_totals : 0 emp : 105 sid : 1939 submit : Submit

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Okay - this was poor syntax on my part but now I'm curious as to why.

I left out quotation marks - the solution is as simple as this: $sid = $_POST["sid"]

Now it works like a champ.

Any takers on why? I'd guess there is a setting in t开发者_运维技巧he php.ini that requires the quotes. Strangely enough, I have other variables called from the POST array that i'm not using quotes for and they're working fine...

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Use Console in FireBug to inspect the POST request to see what is the sid value that is being sent.

If the sid value in request is ok, use var_dump($_POST["sid"]); to see the results on the server.

EDIT: it's considered good PHP style to use the quotes when accessing the associative array because quote-less keys are indistinguishable from constants:

define('myVar',3);
echo $array[myVar]; // retrieves $array[3], not $array['myVar'];

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Try to echo the $sid instead of the <?=:

// Change that
<input name="sid" type="hidden" id="sid" value="<?=$sid?>">

// With that
<input name="sid" type="hidden" id="sid" value="<?php echo $sid; ?>">

also for the test time try to change the input type from hidden to text in order to be 100% sure the $sid contains a value.

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Using quotes for associative array keys is mandatory, and while it may work without them, it's incorrect and erratic behavior is expected.

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I had this same problem, trying to use $_POST[sid] as a variable. I'm am thinking that "sid" is a reserved or restricted variable name, because I changed my variable to $_POST[snid] and it worked just fine. This was my code

$sid = $_POST[sid];
$recipient = "($sid) ($_POST[sid])";
if ($_POST[sid] > 0)
{
    $recipient = "It Worked";
}
print $recipient;

When I posted "&sid=15", the result was:

() (15)

Unbelievable. Impossible, right? All I did was change from using "sid" as the index to "snid", and it worked no problem.

So, don't ever use $_POST[sid].