How to disable before today date in html 5

In this article i have explain how to disable today before date in html 5 calendar

Step 1-
Add the input filed in your html page

<input type="date" name="mydate">

which has input type date

Step 2-

Now i want disable date before today date . for doing this add following javascript code into your page 

 <script>

        var today = new Date().toISOString().split('T')[0];

        document.getElementsByName("mydate")[0].setAttribute('min', today);

    </script>