Adding clear functionality for CalenderExtender Control in ajax tool kit

Hi Friends ,
   I have the same request , i have added couple of lines of code after going through CalenderBehaviour.js as below , it has functionality clear for use  once you done below 10 changes the clear functionality works fine , awesome :)
 
1) Find this._today = null; in the js and add the below code
 //ravishanker maduri added for clear
    this._clear = null
2) Add the below code before the function "get_visibleDate: function () {"
set_clearDate: function (value) {/////ravishanker maduri added for clear
        if (value && (String.isInstanceOfType(value)) && (value.length != 0)) {
            value = new Date(value);
    &nb ...