toggle multiple check boxes

rowers/templates/team_compare_select.html

@@ -6,6 +6,15 @@
 
 {% block content %}
 
+<script>
+  function toggle(source) {
+  checkboxes = document.querySelectorAll("input[type='checkbox']");
+  for(var i=0, n=checkboxes.length;i<n;i++) {
+       checkboxes[i].checked = source.checked;
+  }
+ }
+</script>
+
 
 <div class="grid_12 alpha">
     {% include "teambuttons.html" with teamid=team.id team=team %}
@@ -58,10 +67,12 @@
 
   {% if workouts %}
   
+  <input type="checkbox" onClick="toggle(this)" /> Toggle All<br/>
 
   <table width="100%" class="listtable">
     {{ form.as_table }}
   </table>
+
 {% else %}
 <p> No workouts found </p>
 {% endif %}