1.用javascript判断 [isNaN()]
JS代码：
<script language="javascript">
function check(formname){
if (isNaN(formname.price.value)){
alert('请输入数字');
formname.price.focus();
return false;
}
alert('是数字,通过');
return true;
}
</script>

调用:
<form name="form1" method="post" action="" onsubmit="check(this)">
<input type="text" name="price">
<input type="submit" name="Submit" value="提交">
</form>

2.用VBscript判断[isnumeric()]
跟上面的类似，用isnumeric()函数即可
<script language=vbscript>
sub isnum(param)
if not isnumeric(param) then
msgbox("请输入数字")
end if
end sub
</script>