Show specific modal depending on PHP url variable - php

Question

How I can show a specific modal depending on a variable in php which is modified in the url.
I'm using as responsive framework Bootstrap.
I have a page containing several modals, each corresponding to a product. I need to make a link from other parts of the site to go to page "products.php" and automatically display the required product.
E.g:
href="products.php?prod=1"
So far, I have only succeed in showing the modal when loading the page, but if I add or change the variable, it has no effect, not working at all.
This is what I have:
At the beginning
<?php
//Variable to choose which modal to show, default = 1
$prod = 1;
?>
Then the modal which has an id for identification.
<div class="modal fade" id="product1" tabindex="-1" role="dialog" aria-hidden="true">
<!-- Content of the modal -->
</div>
Then the script that show the modal when the page loads.
<script type="text/javascript">
$(document).ready(function(){
<?php if ($prod == 1) {
echo "$(document).ready(function () {var a = 'PD1'; alert(a); });";
echo "$('#product1').modal('show');";
}elseif ($prod == 2) {
echo "$(document).ready(function () {var a = 'PD2'; alert(a); });";
echo "$('#product2').modal('show');";
};
?>
});
</script>
Any idea?

Answer 1

You not gathering the value of the product variable from the URI. To accomplish this at the top of the page where you have $prod=1; you can put the following line of code :
$prod = (isset($_GET['prod']))?$_GET['prod']:"1";
This tells the system to get the value of the prod= in your url if it can't find it then use "1" as a default.
This is not the ideal answer, there are quite a few reasons not to access $_GET/$_POST variables in this way without proper filtering. I leave that for you to research.

Answer 2

You are doing opposite, should be
<?php if ($prod == "1") { ?>
<script type="text/javascript">
$(document).ready(function(){
var a = 'PD1';
alert(a);
$('#product1').modal('show');
});
</script>
<?php } elseif ($prod == "2") { ?>
<script type="text/javascript">
$(document).ready(function(){
var a = 'PD2';
alert(a);
$('#product2').modal('show');
});
</script>
<?php } ?>