How to validate and disable (start & end) dates less than start date (datepicker)

In some case we want start date should be less than end date, and to disable renaming date

HTML

Script

$(document).ready(function(){
$(“#txtFromDate”).datepicker({
numberOfMonths: 1,
onSelect: function(selected) {
$(“#txtToDate”).datepicker(“option”,”minDate”, selected)
}
});
$(“#txtToDate”).datepicker({
numberOfMonths: 1,
onSelect: function(selected) {
$(“#txtFromDate”).datepicker(“option”,”maxDate”, selected)
}
});
});