The program does not work after a few runs

[shahriar]

see this:

html:

<form method="post"><?php mysearch(); ?>
<div class="hidden"><input type="checkbox" name="link[]" value="art" checked="checked"></div>
<input type="checkbox" name="link[]" value="mix">Mix
<input type="checkbox" name="link[]" value="bro">Bro
<input type="checkbox" name="link[]" value="wood">Wood
<input name="word" placeholder="Word Search..." value="">
<input name="year" placeholder="Year" value="">
<input name="month" placeholder="Month" value="">
<input name="day" placeholder="Day" value="">
<input id="mymenu" name="mytag" value="<?php $post_tags = get_the_tags(); if ( $post_tags ) { echo $post_tags[0]->name; } ?>">
<button type="submit" class="Sbutton">search it</button></form>

 

php:

<?php
function mysearch() {
    $mytag =  $_POST['mytag'];
	$word =  $_POST['word'];
	$year =  $_POST['year'];
    if(isset($year) && !empty($year)) { $year2 = "&year=" . $year; }	
	$month =  $_POST['month'];
	if(isset($month) && !empty($month)) { $month2 = "&month=" . $month; }
	$day =  $_POST['day'];
	if(isset($day) && !empty($day)) { $day2 = "&day=" . $day; }
	
	
    if(isset($_POST['link'])) {
    $name = $_POST['link'];  
    foreach ($name as $link){
    $mycat .= $link . "+";  
    $mycat2 =  $mycat;
    if ($mycat2 == 'art+') { $mycat2 = "/?tag="; }	
    else { $mycat2 = "/category/" . substr($mycat2, 4, -1) . "/?tag="; }
                             }
	$mylink = "http://test.com" . $mycat2 . $mytag . $year2 . $month2 . $day2 . "&s=" . $word;
	header("Location: {$mylink}");
                               }   
                      }
?>

I have written this search box. is very simple.

But I don't know why it only works a few times! And if you click on it one after the other, WordPress will give an error.

Then you have to refresh the page for it to work again. And again, it crashes again after a few times and goes to the error page.

 

Edited May 8, 2020 by shahriar