adding swap button

index.htm

@@ -70,6 +70,7 @@
                 <select id="pointb" name="Point_B">
                   <!-- Options will generated in code -->
                 </select>
+                <button id="swapab" class="btn">Swap</button>
                 <br />    <br />
                 <label for="speed">Travel Speed</label>    <br />
                 <input type="text" id="speed" value="14">    <br />

js/GUI.Utils.js

@@ -39,6 +39,14 @@ $(document).ready(function() {
 			 var stop=$('#route_output :selected').parent().attr('label');
 			 zoomfocus(stop);
 		});
+		$('#swapab').click(function() {
+			var pa = "pointa";
+			var pb = "pointb";
+			$("#pointa").remove();
+			$("#pointb").remove();
+			$("#pointa").val(pb);
+			$("#pointb").val(pa);
+		});
 		$('#calctnd').click(function() {
 
 			removeEntity('arrow');