does Firefox support TD onmouseover, onmouseout, onclick?

<style type="text/css">
..buttonout {
cursorointer;
color: #0000FF;
background-image: url(i/Fur028.jpg);
}
..buttonover {
cursor:hand;
color:#0000FF;
background-color:#CC99CC;
}
</style>
<table border=1 cellspacing=0><tr>
<td style='vertical-align:middle;width:1.75in;border-top:none;border-left:
none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext
1.0pt;
padding:0in 5.4pt 0in 5.4pt'
class="buttonout"
onMouseOver="javascript:this.className='buttonover ';"
onMouseOut="javascript:this.className='buttonout'; "
onClick="javascript:location.href='contactus.php'; ">
blah
</td>
</tr></table>

dreamweaver warns me this is not supported in NS6. Should that bother me?
(where would I go to find out browser usage statistics?)
more importantly, will firefox support this?