php radio group strange behavior

Question

I have a group of radio buttons in a multiple select quiz form and i'm having a bit of trouble with the buttons. When I try to click any other radio button apart from the 1st one, it instantly shows the 1st radio button as selected and it takes 3-4 attempts to finally mark the desired button. This is my code if you want to test it:

               <form action="<?php echo $editFormAction; ?>" method="post" name="form" target="_self" id="form1">
          <table width="100%" border="0" cellpadding="2" cellspacing="0">
                <tr>
                  <td class="greentitle">Question 1</td>
                  <td>
                  <label>
                    <input type="radio" name="environment" value="1" />1
                    <input type="radio" name="environment" value="2" />2
                    <input type="radio" name="environment" value="3" />3
                    <input type="radio" name="environment" value="4" />4
                    <input type="radio" name="environment" value="5" />5
                  </label>
                  </td>
                </tr>
                <tr>
                  <td class="greentitle">Question 2</td>
                  <td>
                  <input name="speed" type="radio" value="1" />1
                  <input name="speed" type="radio" value="2" />2
                  <input name="speed" type="radio" value="3" />3
                  <input name="speed" type="radio" value="4" />4
                  <input name="speed" type="radio" value="5" />5
                  </td>
                </tr>
                <tr>
                  <td class="greentitle">Question 3</td>
                  <td>
                  <input name="quality" type="radio" value="1" />1
                  <input name="quality" type="radio" value="2" />2
                  <input name="quality" type="radio" value="3" />3
                  <input name="quality" type="radio" value="4" />4
                  <input name="quality" type="radio" value="5" />5 
                  </td>
                </tr>
                <tr>
                  <td class="darkgrey">&nbsp;</td>
                  <td><input name="submit" type="submit" class="formmed" id="submit" value="Submit" tabindex="5"  style="width:200px;"/></td>
                </tr>
              </table>
        </form>

Answer 1

I have gone through your code. Remove the label tag from the first radio(name="environment") group. Then it will work fine.