onkeydown事件不触发,该怎么解决

onkeydown事件不触发
<input type=text class="InputNumber" DataType="+" iQty="" minQty="0" onkeydown="NewLine()" onchange="CheckInvQty(this,0)" value="" onfocus="InputData()"/>
我在table中有这样一个input，有onkeydown onchange onfocus三个事件，唯独onkeydown不被触发，我这样写有什么问题么

[解决办法]
http://jsfiddle.net/5XfsB/2/
测试了没问题
[解决办法]
试试 onkeydown="return NewLine(event);"

JScript code

function NewLine(e){var keynumvar keycharvar numcheckif(window.event) // IE  {  keynum = e.keyCode  }else if(e.which) // Netscape/Firefox/Opera  {  keynum = e.which  }keychar = String.fromCharCode(keynum)numcheck = /\d/return !numcheck.test(keychar)}