话不多说,直接上代码
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<script type="text/javascript">
    var detail_div = 1;
    function add_div() {
        var e = document.getElementById("details");
        var div = document.createElement("div");
        div.className = "form-group";
        div.id = "details" + detail_div;
        div.innerHTML = e.innerHTML;
        document.getElementById("form").appendChild(div);
        detail_div++;
    }
    
    function del_div() {
      if(detail_div >1){
            var id = "details" + (detail_div - 1).toString();
            var e = document.getElementById(id);
            document.getElementById("form").removeChild(e);
            detail_div--;
        }
    }
    function number(){
        var number = document.getElementById("number");
        var value = number.value;
        //如果文本值为空,设置为1
        if (value=="") {
            number.value = 1;
        }
        //如果文本值为非纯数字,设置为1
        //isNaN()是否为非法数字
        if (isNaN(value)) {
            number.value = 1;
        }
        //如果文本值小于1,设置为1
        if (parseInt(value)<=1) {
            number.value = 1;
        }
    }
</script>
<body>
<form id="form" role="form" method="post">
    <div>
        <label for="details" >演示</label>
        <button type="button"  id="add-btn" onclick="add_div()">+</button>   
        <button type="button"  id="del-btn" onclick="del_div()">-</button>
    </div>
    <div  id="details">
        <div>
            <label for="receivable" >选项</label>
           Label:<input  id="receivable" onBlur="number()"  />
            value:<input  id="receivable1" onBlur="number()"  />
        </div>
    </div>
</form>
</body>
</html>演示图


