shop/application/admin/view/unishop/order/refundShow.html

<form id="add-form" class="form-horizontal" role="form" data-toggle="validator" method="POST" action="">

    <div class="form-group">
        <label class="control-label col-xs-12 col-sm-2">订单ID</label>
        <div class="col-xs-12 col-sm-8">
            <input id="order_id" class="form-control" readonly="readonly"  name="id" type="number" value="{$id}">
        </div>
    </div>
    <div class="form-group">
        <label class="control-label col-xs-12 col-sm-2">退款金额</label>
        <div class="col-xs-12 col-sm-8">
            <input id="refund_fee" class="form-control"  name="id" type="number" value="{$id}">
        </div>
    </div>
</form>
<script>
    function checknum(obj)
    {
        //如果输入非数字，则替换为''
        obj.value = obj.value.replace(/[^\d\.]/g, '');
        //必须保证第一个为数字而不是.
        obj.value = obj.value.replace(/^\./g,'');
        //前两位不能是0加数字
        obj.value = obj.value.replace(/^0\d[0-9]*/g,'');
        //保证只有出现一个.而没有多个.
        obj.value = obj.value.replace(/\.{2,}/g,'.');
        //保证.只出现一次，而不能出现两次以上
        obj.value = obj.value.replace('.','$#$').replace(/\./g,'').replace('$#$','.');
        //只能输入两位小数
        obj.value = obj.value.replace(/^(\-)*(\d+)\.(\d\d).*$/,'$1$2.$3');
    }

    $('refund_fee').on('input',function () {
        checknum(this);
    })
</script>