setDifference = function(form)
    {
        var x = document.forms.search.arrival.value;
        var y = document.forms.search.departure.value;
		       
        //assuming that the delimiter for dt time picker is a '/'.
        var arr1 = x.split('/');
        var arr2 = y.split('/');
		
		if(arr1[1] != 'dd' && arr2[2] != 'dd') {

        var dt1 = new Date();
        dt1.setFullYear(arr1[2], arr1[1], arr1[0]);
        var dt2 = new Date();
        dt2.setFullYear(arr2[2], arr2[1], arr2[0]);
        
        document.forms.search.nights.value = (dt2.valueOf() - dt1.valueOf()) / (60 * 60 * 24 * 1000)
		
		} else {
		
		document.forms.search.nights.value = '';
		
		}
		
    }