I'm using the following code to share using custom buttons on my website:
<div id="share_buttons">
<img src="images/facebook.png" onclick="popup('http://www.facebook.com/share.php?u=<?php echo $URL; ?>', 'Share on Facebook');">
<img src="images/twitter.png" onclick="popup('http://twitter.com/intent/tweet?status=<?php echo $coil->name . " at: " . $URL; ?>', 'Share on Twitter');">
<img src="images/googleplus.png" onclick="popup('https://plus.google.com/share?url=<?php echo $URL; ?>', 'Share on Google+');">
</div>
The issue is that when I share the page it selects the image from the button that was clicked. I'm not using any of Twitter's, Facebooks, or google's API's because they don't allow me to use custom images (to my knowledge). I want to define an image for the share to have when someone shares it. How would this be done? Thanks.