Validate if date is before date of current date in sugarcrm? -

i have created date (calender) field in sugarcrm ie. date , date.

if user enters date before date of current date have generate alert.

example: if today date 03-june-2015 if picks 02-june-2015 or before 02 june have generate alert.

you need call function check_start_date() onchange event of both datepicker. i.e. startdate , enddate

function check_start_date() {      var startdate = $('#start_date').val();     var enddate = $('#end_date').val();      var startdateval;     var enddateval;      /* check field must not empty */     if (startdate != '' || enddate != '') {         startdateval = date.parse(startdate);         enddateval = date.parse(enddate);         if (enddateval >= startdateval ) {             return true;         } else {             alert("end date should greater start date");             return false;         }     } else {         return false;     } }