prog.js

$(document).ready(function() {


    from = $( "#from" )
        .datepicker({
            dateFormat: "yy-mm-dd",
            defaultDate: "+1w",
            changeMonth: true,
            numberOfMonths: 1
        })
        .on( "change", function() {
            to.datepicker( "option", "minDate", getDate( this ) );
        }),
    to = $( "#to" ).datepicker({
            dateFormat: "yy-mm-dd",
            defaultDate: "+1w",
            changeMonth: true,
            numberOfMonths: 1
        })
        .on( "change", function() {
            from.datepicker( "option", "maxDate", getDate( this ) );
        });
 
function getDate( element ) {
    var date;
    try {
        date = $.datepicker.parseDate( dateFormat, element.value );
    } catch( error ) {
        date = null;
    }

    return date;
}

});