Post on Twitter using JavaScript

HTML Block:

<div> <a href="javascript: void(0)" onclick="TwitterPopup('https://twitter.com/share?url= YourSiteURL&text=TextToPostOnTwitter')" ></a></div>

JavaScript Block:

function TwitterPopup(url) 

{

        var width  = 500;

        var height = 300;

        var left   = (screen.width  - width)/2;

        var top    = (screen.height - height)/2;

        var params = 'width='+width+', height='+height;

        params += ', top='+top+', left='+left;

        params += ', directories=no';

        params += ', location=no';

        params += ', menubar=no';

        params += ', resizable=no';

        params += ', scrollbars=no';

        params += ', status=no';

        params += ', toolbar=no';

        var twtPopupTitle = 'Post on Twitter';

        if (navigator.appName == 'Microsoft Internet Explorer')

        {

               twtPopupTitle = null;

        }  

        var newwin =  window.open(url, twtPopupTitle, params);

        if (window.focus) {

               newwin.focus();    

        }

        return false;

}

            

!function(d, s, id) { var js, fjs = d.getElementsByTagName(s)[0], p = /^http:/.test(d.location) 

? 'http' : 'https'; if (!d.getElementById(id)) { js = d.createElement(s); js.id = id; js.src = p + '://platform.twitter.com/widgets.js'; fjs.parentNode.insertBefore(js, fjs); } } (document, 'script', 'twitter-wjs');

Reference:
https://dev.twitter.com/docs/tweet-button