现在购物车的问题是:初始化的合计只有第一行是正常的其它不能显示,点击加加减减其它行的表单也同时在加减,删除按钮也只有第一行起作用,总金额合计不了,请朋友们帮忙看看,给个建义也好

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script src="../jQuery/jquery-3.2.1.min.js" type="text/javascript"></script>
<script language="javascript" type="text/javascript">
$(document).ready(function(){
//全选
$('#checkbox').click(function(){
$('.pox input').prop('checked',true);
$('#checkbox2').prop('checked',false);
});
//取消全选
$('#checkbox2').click(function(){
$('.pox input').prop('checked',false);
$('#checkbox').prop('checked',false);
});
//首先显示合计的金额
var zhi = $('.text').val();
$('#hj').text($('#jg').text() * zhi);
//按钮数字加加
$('#jia').click(function(){
var num = $('.text').val();
var n = ++num;
$('.text').val(n);
$('#hj').text($('#jg').text() * $('.text').val());
});
//按钮数字减减
$('#jian').click(function(){
var num = $('.text').val();
if(num > 1){
var n = --num;
$('.text').val(n);
$('#hj').text($('#jg').text() * $('.text').val());
}else{
alert('此商品不能少于一件!');
}
});
//删除节点
$('#del').click(function(){
if(confirm('你确认要删除嘛!')){
$(this).closest('tr').remove();
return false;
}
});
//表格合计相加
});
//disabled
</script>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
body {
margin-left: 0px;
margin-top: 0px;
margin-right: 0px;
margin-bottom: 0px;
}
.pox{
border:1px #999 solid;
}
.text{
width:100px;
}
#totle{
font-size:12pt;
font-weight:bold;
}
body,td,th {
font-size: 10pt;
}
</style>
</head>
<body><br />
<table width="700" border="0" align="center" cellpadding="0" cellspacing="0" height="30">
<tr>
<td width="150" bgcolor="#FFCC66">
<input type="checkbox" name="checkbox" id="checkbox" />全选
<input type="checkbox" name="checkbox2" id="checkbox2" />取消
</td>
<td width="150" bgcolor="#FFCC66">品名</td>
<td width="60" align="center" bgcolor="#FFCC66">单价</td>
<td width="200" align="center" bgcolor="#FFCC66">数量</td>
<td width="80" align="center" bgcolor="#FFCC66">合计</td>
<td width="60" align="center" bgcolor="#FFCC66">操作</td>
</tr>
</table>
<form action="">
<div class="pox">
<table width="700" border="1" align="center" cellpadding="0" cellspacing="0" height="180">
<tr>
<td width="40" align="center" bgcolor="#FFFFCC">
<input type="checkbox" />
</td>
<td width="260" align="center" bgcolor="#FFFFCC">衬衫</td>
<td width="60" align="center" bgcolor="#FFFFCC"><span id="jg">28</span></td>
<td width="200" align="center" bgcolor="#FFFFCC">
<input type="button" name="button" id="jia" value="+" />
<input name="textfield" type="text" class="text" id="textfield" value="1"/>
<input type="button" name="button2" id="jian" value="-" />
</td>
<td width="80" align="center" bgcolor="#FFFFCC"><span id="hj"></span></td>
<td width="60" align="center" bgcolor="#FFFFCC"><span id="del" style='cursor:pointer'>删除</span></td>
</tr>
<tr>
<td align="center" bgcolor="#CCFFFF">
<input type="checkbox" />
</td>
<td align="center" bgcolor="#CCFFFF">书</td>
<td align="center" bgcolor="#CCFFFF"><span id="jg">20</span></td>
<td align="center" bgcolor="#CCFFFF">
<input type="button" name="button" id="jia" value="+" />
<input name="textfield" type="text" class="text" id="textfield" value="1"/>
<input type="button" name="button2" id="jian" value="-" />
</td>
<td align="center" bgcolor="#CCFFFF"><span id="hj">20</span></td>
<td align="center" bgcolor="#CCFFFF"><span id="del" style='cursor:pointer'>删除</span></td>
</tr>
<tr>
<td align="center" bgcolor="#FFFFCC">
<input type="checkbox" />
</td>
<td align="center" bgcolor="#FFFFCC">笔</td>
<td align="center" bgcolor="#FFFFCC"><span id="jg">5</span></td>
<td align="center" bgcolor="#FFFFCC">
<input type="button" name="button" id="jia" value="+" />
<input name="textfield" type="text" class="text" id="textfield" value="1"/>
<input type="button" name="button2" id="jian" value="-" />
</td>
<td align="center" bgcolor="#FFFFCC"><span id="hj">5</span></td>
<td align="center" bgcolor="#FFFFCC"><span id="del" style='cursor:pointer'>删除</span></td>
</tr>
<tr>
<td align="center" bgcolor="#CCFFFF">
<input type="checkbox" />
</td>
<td align="center" bgcolor="#CCFFFF">荼</td>
<td align="center" bgcolor="#CCFFFF"><span id="jg">12.5</span></td>
<td align="center" bgcolor="#CCFFFF">
<input type="button" name="button" id="jia" value="+" />
<input name="textfield" type="text" class="text" id="textfield" value="1"/>
<input type="button" name="button2" id="jian" value="-" />
</td>
<td align="center" bgcolor="#CCFFFF"><span id="hj">12</span></td>
<td align="center" bgcolor="#CCFFFF"><span id="del" style='cursor:pointer'>删除</span></td>
</tr>
<tr>
<td align="center" bgcolor="#FFFFCC">
<input type="checkbox" />
</td>
<td align="center" bgcolor="#FFFFCC">糖</td>
<td align="center" bgcolor="#FFFFCC"><span id="jg">10.4</span></td>
<td align="center" bgcolor="#FFFFCC">
<input type="button" name="button" id="jia" value="+" />
<input name="textfield" type="text" class="text" id="textfield" value="1"/>
<input type="button" name="button2" id="jian" value="-" />
</td>
<td align="center" bgcolor="#FFFFCC"><span id="hj">10</span></td>
<td align="center" bgcolor="#FFFFCC"><span id="del" style='cursor:pointer'>删除</span></td>
</tr>
<tr>
<td bgcolor="#FFCCCC"> </td>
<td bgcolor="#FFCCCC"> </td>
<td bgcolor="#FFCCCC"> </td>
<td colspan="3" bgcolor="#FFCCCC">合计:<strong>¥</strong><strong id="totle"></strong></td>
</tr>
</table>
</div>
</form>
</html>