<form action="test.asp" method="post" onsubmit="return (!isNaN(document.all.num.value)&&document.all.num.value.replace(/\s/g,'')!='')">
<input type=text name="num">
<input type=submit>
</form>
<input type=text name="num">
<input type=submit>
</form>
document.all.num.value.replace(/\s/g,'')!=''替换所有空白字符
<!--
function checkNum(){
reg=/\D/;
if (reg.test(document.all.num.value))
alert("输入的是数字!")
else
alert("输入的不是数字!")
// -->
</script>
<HTML><HEAD><TITLE></TITLE>
<META content="text/html; charset=gb2312" http-equiv=Content-Type>
<META content="MSHTML 5.00.3809.1800" name=GENERATOR></HEAD>
<BODY>
<FORM name=form1><INPUT maxLength=4 name=n>年 <INPUT maxLength=2 name=y>月 <INPUT
maxLength=2 name=r>日 <INPUT maxLength=6 name=rksl>入库数量 </FORM>
<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;
}
}
document.form1.n.onkeypress = blockA;
document.form1.y.onkeypress = blockA;
document.form1.r.onkeypress = blockA;
function blockB(t)
{
if (document.layers)
var keyChar =e.which;
if (document.all)
var keyChar =event.keyCode;
if (keyChar>57 || keyChar<46 || (keyChar>46 && keyChar<49)) //查ASCII码的值,限制keyChar的范围,这样可以控制键盘输入
{
alert('请输入数字!');
return false;
}
}
document.form1.rksl.onkeypress=blockB;
</SCRIPT>
</BODY></HTML>