<table border="0" width="200" id="myexample" style="border:5px solid green">
<tr>
<td> <br></td>
</tr>
</table>
<script language="JavaScript1.2">
<!--

function flashit(){
if (!document.all)
return
if (myexample.style.borderColor=="green")
myexample.style.borderColor="red"
else
myexample.style.borderColor="green"
}
setInterval("flashit()", 500)
//-->
</script>