Jquery Datepicker - Calculate Date Difference

I'm new at this and I really need your help because I've been struggling for days with this… I want to calculate days between two dates chosen with datepicker. Am I on the right

Solution 1:

working for me after making this change

var start = $('#datepicker').datepicker('getDate');
    var end   = $('#datepicker1').datepicker('getDate');
    var days   = (end - start)/1000/60/60/24;
    alert(days);

jsfiddle: http://jsfiddle.net/diode/L2et3/3/