Fixup "Zoom to selection" checkbox to use a label

git-svn-id: https://flot.googlecode.com/svn/trunk@250 1e0a6537-2640-0410-bfb7-f154510ff394

examples/selection.html

@@ -35,7 +35,7 @@
        in the "plotselected" event triggered. Enable the checkbox
        below and select a region again.</p>
 
-    <p><input id="zoom" type="checkbox">Zoom to selection.</input></p>
+    <p><label><input id="zoom" type="checkbox" />Zoom to selection.</label></p>
 
 <script id="source" language="javascript" type="text/javascript">
 $(function () {