counting classes

counting classes

Hey Guys,
I`m looking for a way to count the classes of some table rows. My big problem is, that i don`t know the class names. So, they should be counted variable.
  1. <table id="testTable">
  2.     <tr class="class1">

  3.         <td class="multiplier">1</td>

  4.         <td>class1</td>

  5.         <td>class1</td>

  6.         <td>class1</td>

  7.     </tr>

  8.     <tr class="class1">

  9.         <td class="multiplier">2</td>

  10.         <td>class1</td>

  11.         <td>class1</td>

  12.         <td>class1</td>

  13.     </tr>

  14.     <tr class="class2">

  15.         <td class="multiplier">1</td>

  16.         <td>class2</td>

  17.         <td>class2</td>

  18.         <td>class2</td>

  19.     </tr>

  20.     <tr class="class1">

  21.         <td class="multiplier">1</td>

  22.         <td>class1</td>

  23.         <td>class1</td>

  24.         <td>class1</td>

  25.     </tr>

  26.     <tr class="class2">

  27.         <td class="multiplier">1</td>

  28.         <td>class2</td>

  29.         <td>class2</td>

  30.         <td>class2</td>

  31.     </tr>

  32.     <tr class="class1">

  33.         <td class="multiplier">1</td>

  34.         <td>class1</td>

  35.         <td>class1</td>

  36.         <td>class1</td>

  37.     </tr>

  38.     <tr class="class3">

  39.         <td class="multiplier">2</td>

  40.         <td>class3</td>

  41.         <td>class3</td>

  42.         <td>class3</td>

  43.     </tr>

  44. </table>
Here is a test fiddle: http://jsfiddle.net/JR7Mz/1/

I`ll hope you can help me. :-)
snuwie