You will need to use JavaScript. I'm not in a position to develop anything right now but here are a couple of links for inspiration.
- stackoverflow.com/questions/9822371/sele...rdinates-with-jquery
- www.emanueleferonato.com/2006/09/02/clic...tes-with-javascript/
- stackoverflow.com/questions/9822371/sele...rdinates-with-jquery
- www.emanueleferonato.com/2006/09/02/clic...tes-with-javascript/