<input type=button value=a onmouseover="document.all.aa.innerText='a'" >
<input type=button value=b onmouseover="document.all.aa.innerText='b'" >
<input type=button value=b onmouseover="document.all.aa.innerText='b'" >
<input value=b type=button onmouseover='aa.innerText="b"'>
<Div id="aa">a</div>
<input value=b type=button onmouseover='aa.innerText="b"'>
<Div id="aa">a</div>
<input type=button value=b onmouseover="document.all.aa.innerHTML='<font color=red>b</font>'" >
<input type=button value=b onmouseover="document.all.aa.innerText='b'" >