Is access keys are restricted only to links/anchor tags?

Code:
<td accesskey="c" id=comp onmouseout=btnTimer()
 onmouseover=showLayer("company",'comp')>Company</td>
doesn't seems to be working in firefox?

What's the issue?

I used the following code,

Code:
<td id=comp onmouseout=btnTimer() 
onmouseover=showLayer("company",'comp')>Company</td>
<accesskey="c" targetid="comp">
can use use like this?