always hiding a button after clicking on it using php and css - php

Question

I have this php code which hide the download button after clicking on it one time by changing the ID from 0 to 1 .. after that if another time the user signed in , it removes the button using a simple css hide code.
here is my code :
<?php
$result = #mysql_query("SELECT * FROM scode WHERE updated= 1 and coden ='$username'");
if ($_POST[downloadTheFile]== "downloadTheFile")
{
$upd_art = "update scode set downloaded='".$_POST[t11] ."' where id='$_SESSION[userid]'";
mysql_query($upd_art) or die(mysql_error());
}
if($row['downloaded']==1)
{
echo "<style>
.thedownloadbutton {display:none;}
</style>";
}
?>
<form class="thedownloadbutton" method="get" action="<? echo '../download/'.$item_downloadlink .'.zip' ; ?>">
<button type="submit" name="downloadTheFile" value="downloadTheFile">Download </button>
<input name="t11" type="hidden" size="2" value="1">
</form>
(just for clarifying: updated =1 is a field that'll open the download page.. if the updated =1 then there is a download page )
I don't know why it doesn't work ..
can you help me please and till me which part is the wrong part ?
I know it's a bad way to hide an element using css , is there another suggestion ?

Answer 1

$_POST[downloadTheFile] should be $_POST['downloadTheFile']
if($row['downloaded']!=1)
{
echo '<button type="submit" name="downloadTheFile" value="downloadTheFile">Download </button>';
}

Answer 2

so there were some problems in this code .. it wasn't professional at all so I used this new code which has a button that update the number from 0 to 1 on the database
(that will tell the download button to not show after that)
then shows the download button
<?
$res = mysql_query("SELECT downloaded FROM scode WHERE id='$_SESSION[userid]'");
$row = mysql_fetch_array($res);
// echo $row['downloaded'];
echo '<br>';
?>
<form method="POST" action=''>
<?
if($row['downloaded'] ==='0')
{
echo "<input type='submit' name='button1' value='click to show the download link' onclick ='validatea(); return false;' />";
//echo '<button type="submit" formmethod="post" name="downloadTheFile" value="downloadTheFile">Download </button>';
?>
</form>
<?
if (isset($_POST['button1']))
{
?> <form class="aaa" method="POST" action="<? echo "../download/".$item_downloadlink .".zip" ; ?>">
<? ;
?> <input type='submit' name='submit' value='download' onclick ='validate(); return false;' /> <? ;
echo"</form>";
$upd_art = "update scode set downloaded='1' where id='$_SESSION[userid]'";
mysql_query($upd_art) or die(mysql_error());
}
}
else {
echo "you already downloaded the file , if you have any problem please contact us";
echo"<br>";
}
?>