button.js

var calClick = function() {
    //Calendar was clicked..
};


var oButton = new YAHOO.widget.Button({
    type: "menu",
    id: "calendarpicker",
    label: "Choose A Date",
    menu: oCalendarMenu,
    container: "datefields"
});
oButton.addClass('calpicker');
oButton.on('click', calClick);

var oButton2 = new YAHOO.widget.Button({
    type: "menu",
    id: "calendarpicker2",
    label: "Choose A Date",
    menu: oCalendarMenu2,
    container: "datefields2"
});
oButton2.addClass('calpicker');
oButton2.on('click', calClick);