input怎么限制只能输入数字？

js实现

1.简单

<script language=javascript>

function onlyNum()

{

  if(!((event.keyCode>=48&&event.keyCode<=57)||(event.keyCode>=96&&event.keyCode<=105)))

    event.returnValue=false;

}

</script>

<input onkeydown="onlyNum();">

2.完善

<script language=javascript>

function onlyNum()

{

 if(!(event.keyCode==46)&&!(event.keyCode==8)&&!(event.keyCode==37)&&!(event.keyCode==39))

  if(!((event.keyCode>=48&&event.keyCode<=57)||(event.keyCode>=96&&event.keyCode<=105)))

    event.returnValue=false;

}

</script>

<input onkeydown="onlyNum();">