我用javascript计算出来的值怎么放在网页上 急！！！！！！

<html><head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<SCRIPT LANGUAGE=javascript>
function sumNum(num1,num2)
{
    var sum = num1 + num2;    tab_rest.innerText="Result:"+sum ;
}
</SCRIPT>
</head><body>
<button onclick="sumNum(1,2)">sum</button>
<table border="1" width="100%" id="table1">  <tr>
    <td id="tab_rest">　Result:</td>
  </tr>
</table>
</body>
</html>

解决方案 »

  1.   

    若是一定要將sumNum(num1,num2)的功能放在前臺則只有這樣了:
    <html><head>
    <meta http-equiv="Content-Type" content="text/html; charset=gb2312">
    <SCRIPT LANGUAGE=javascript>
    function sumNum(num1,num2)
    {
        var sum = num1 + num2;
    }
    function window.onload()
    {
        tdResult.innerHTML = sumNum(num1,num2);
    }
    </SCRIPT>
    </head><body>
    <table border="1" width="100%" id="table1">  <tr>
        <td id=tdResult>　Result:</td>
      </tr>
    </table>
    </body>
    </html>
      

  2.   

    <html><head>
    <meta http-equiv="Content-Type" content="text/html; charset=gb2312">
    <SCRIPT LANGUAGE=javascript>
    function sumNum(num1,num2)
    {
        var sum = num1 + num2;
    var resultTD =document.getElementById("resultTd");
    resultTD.innerText=resultTD.innerText+sum;}
    </SCRIPT>
    </head><body>
    <table border="1" width="100%" id="table1">  <tr>
        <td id="resultTD">　Result:</td>
      </tr>
    </table>
    <input type="button" onclick="sumNum(9,10)" value="9+10">
    </body>
    </html>