changing the slected css class

<td class="hover" onmouseover="this.class='normal'">


this does not work what do i need to change to make it change trhe class on mouse over?

<td class="regclass" onmouseover="Javascript: this.className='hoverclass'" onmouseout=
"Javascript: this.className='regclass'">

<td class="hover" onmouseover="this.className='normal'">