How can I check that the date entered in a textbox is less than today's date using java script?

I m using code

var currentDate_Month = new Date().valueOf().getMonth();

        var currentDate_Date = new Date().getDate();

        var currentDate_Year = new Date().getFullYear();

        var EnterDate_Month = new Date(document.getElementById('ctl00_ContentPlaceHolder1_txtDateReceived').value).getMonth();

        var EnterDate_Date = new Date(document.getElementById('ctl00_ContentPlaceHolder1_txtDateReceived').value).getDate();

        var EnterDate_Year = new Date(document.getElementById('ctl00_ContentPlaceHolder1_txtDateReceived').value).getFullYear();



        if(EnterDate_Year<currentDate_Year) {

          if(EnterDate_Month<currentDate_Month) {

            if(EnterDate_Date<currentDate_Date) {

            }

           }

          }

         else {   

            str += '</br>* Date should be Less than or equals to current Date.';

            return false;

         }

But to my surprise the current date coming in the textbox control is Sat Jun 7 2014 when viewing it by -

new Date(document.getElementById('ctl00_ContentPlaceHolder1_txtDateReceived').value).toDateString();

Why is it returning the date in this format? (the date in text box is in format dd/mm/yyyy)

thanks in advance.