Add the class social-button to the links you want to open on a modal window.

modal-share.js

	function modalPopup(url, width, height) {
	  var left = (screen.width / 2) - (width / 2),
	      top = (screen.height / 2) - (height / 2);
	  window.open(
	    url,
	    "",
	    "menubar=no,toolbar=no,resizable=yes,scrollbars=yes,width=" + width + ",height=" + height + ",top=" + top + ",left=" + left
	  );
	}
	$(".social-button").on("click", function(e) {
	  e.preventDefault();
	  modalPopup($(this).attr("href"), 500, 300);
	});