Minor cleanup of syntax

Author: tjvantoll

chapter12/03-flipping-tooltip-with-arrows.html

@@ -62,8 +62,8 @@
 <script>
 	$( "#amount" ).tooltip({
 		position: {
-			my: "center bottom",
-			at: "center top-10",
+			my: "bottom",
+			at: "top-10",
 			collision: "flip",
 			using: function( position, feedback ) {
 				$( this ).addClass( feedback.vertical )