<script language="javascript">
<!--
if (document.layers)
document.captureEvents(event.KeyPress);
function blockA(e) {
if (document.layers)
var keyChar =e.which;
if (document.all)
var keyChar =event.keyCode;
if (keyChar>57 || keyChar<48)
{
alert('请输入数字!');
return false;
}