more robust race form

rowers/templates/race_submit.html

@@ -31,17 +31,35 @@
     <p>Select one of the following workouts that you rowed within the race window</p>
     <table width="100%">
       <tr>
-      {% for field in w_form.hidden_fields %}
-      {{ field }}
-      {% endfor %}
-      {% for field in w_form.visible_fields %}
-      <td>
+        {% for field in w_form.hidden_fields %}
         {{ field }}
-      </td>
+        {% endfor %}
+        {% for field in w_form.visible_fields %}
+        <td>
+          {{ field.label }}
+          {{ field }}
+        </td>
       {% endfor %}
       </tr>
     </table>
   </div>
+  <div class="grid_6 omega">
+    <p>The "Only Evaluate After" field allows you to tell the site to
+      discard the first N minutes fo the workout. This is useful if you
+      paddled through the start polygon as part of your warming up.
+      Fill out the
+      time at which you want to start the evaluation, or leave empty to
+      evaluate the entire workout. </p>
+    <p>Use any of the following formats:
+      <ul>
+        <li>H:MM:SS.d, e.g. 1:45:00.0 for one hour and 45 minutes</li>
+        <li>H:MM:SS, e.g. 1:45:00 for one hour and 45 minutes</li>
+        <li>MM:SS.d, e.g. 30:00.0 for thirty minutes</li>
+        <li>MM, e.g. 30 for thirty minutes</li>
+      </ul>
+    </p>
+
+  </div>
 </div>
 <div class="grid_2 prefix_2 suffix_8">
   {% csrf_token %}