Here's one specific for your code:
var date = $('#datepicker').datepicker({ dateFormat: 'dd-mm-yy' }).val();
More general info available here:
- http://api.jqueryui.com/datepicker/#option-dateFormat - http://api.jqueryui.com/datepicker/#utility-formatDate

Here's one specific for your code:
`var date = $('#datepicker').datepicker({ dateFormat: 'dd-mm-yy' }).val();`
More general info available here:
- http://api.jqueryui.com/datepicker/#option-dateFormat - http://api.jqueryui.com/datepicker/#utility-formatDate