比较2日期javascript上的错误[重复]

Question

Possible Duplicate:
Compare 2 dates with JavaScript

i have this code on javascript

function calculate() {
  var departing = document.getElementById('tickets_expiry_date_departing').value;
  var returning = document.getElementById('tickets_expiry_date_returning').value;
  if (returning > departing){ alert("Error"); } else { return true; }
}

then i call this function on

<input
  class="txtFieldDate"
  name="tickets_expiry_date_returning"
  id="tickets_expiry_date_returning"
  value="<?php echo $_POST["tickets_expiry_date_returning"]; ?>"
  readonly="readonly"
  onChange="calculate();"/>

When the element with id tickets_expiry_date_returning has a value that I consider being less than the value of the element with id tickets_expiry_date_departing I should get an alert displaying the error but I don't. Why?

Answer 1

i think you are doing some thing like this if you have date picker with formate like 25-06-2012 on both of your inputs than the below code will work

 function calculate(){
 if($('#tickets_expiry_date_returning').val().length && 
      $('#tickets_expiry_date_departing').val().length){
            var st_split = $('#tickets_expiry_date_returning').val().split('-');
            var et_split = $('#tickets_expiry_date_departing').val().split('-');
            var start_date = new Date(st_split[0], (st_split[1] - 1), st_split[2]);
            var end_date   = new Date(et_split[0], (et_split[1] - 1), et_split[2]);
            if(start_date > end_date){
                alert("Error");
                return false;
            }
        }
 }