用js制作一个计算器

使用js制作计算器

<!doctype html>
<html lang="en">
 <head>
  <meta charset="UTF-8">
  <meta name="Generator" content="EditPlus®">
  <meta name="Author" content="">
  <meta name="Keywords" content="">
  <meta name="Description" content="">
  <title>Document</title>
<script type="text/javascript">

//相加
function add(){
var first=0;
jai=Number(document.getElementById("text").value);

var scoent=0;
jia=Number(document.getElementById("text2").value);

var sum=0;
sum=jai+jia;
document.getElementById("jieg").value=sum;
}

//相减
function delect(){

var jian=0;
jian=jai-jia;
document.getElementById("jieg").value=jian;
}

//相乘

function chen(){

var ce=0;
ce=jai*jia;
document.getElementById("jieg").value=ce;
}

//相除

function chu(){

var cu=0;
cu=jai/jia;
document.getElementById("jieg").value=cu;
}

</script>

 </head>
 <body>
  <table style="background:red">
  <tr>
  <td colspan="4" align="center">购物简易计算器</td>

  </tr>

    <tr>
      <td>第一个数</td>
    <td colspan="3"><input type="text" id="text"></td>

    </tr>

      <tr>
        <td>第二个数</td>
    <td colspan="3"><input type="text" id="text2"></td>

      </tr>

        <tr>

          <td><input type="submit" value="+" style="width:100% " onclick="add()"></td>
          <td><input type="submit" value="—" style="width:100% " onclick="delect()"></td>
          <td><input type="submit" value="X" style="width:100% " onclick="chen()"></td>
          <td><input type="submit" value="/" style="width:100% " onclick="chu()"></td>
        </tr>

          <tr>
            <td>计算结果</td>
    <td colspan="3"><input type="text" id="jieg" /></td>

          </tr>

  </table>

 </body>
</html>