What's the best practice to create an image button that sends a value and runs a php script (that executes a mySQL query) when clicked. The button has to be an image and not a default submit type of button. I've been googling this for a few days and I still can't find a sutable answer. I could use GET and make a few image buttons (images with links that contain values) on the page that redirect to itself which then I can collect with
if (isset($_GET['variable']))
but I don't really want the user to see the values. I tried creating a form which has only one button in it that when clicked will reload the page and I could capture and use the value with
if (isset($_POST['submit_value'])) {$var = $_POST['submit_value']; }
but I can't seem to make this work, at least not when the button is an image. So if anyone knows a decent way to do this, please share. It doesn't have to be AJAX e.g. page reload is perfectly fine. I'm guessing that I need JavaScript to do this but I don't really know JavaScript so a working example would be nice.
SELF-ANSWER
Thank you for all of your answers. I found that the simplest working way to go with is to create a form with an input type of image that makes the submit and an input type of hidden that carries that value.
<form action="some_page.php" method="POST">
<input type="hidden" name="variable" value="50" />
<input type="image" src="image.png" name="submit" />
</form>
And on the PHP side I use this to catch the value.
if (isset($_POST['variable'])) { $var = $_POST['variable']; }
This is the most suitable solution for my problem. Thank you all again for your speedy responses.