javascript - Javascript 函数 ID

Question

<label for="dessert">What is your favourite dessert?*</label>
<input type="text" id="dessert" onchange="checkForm()"><br>
<div id="dessertmsg">  </div>

<input type="submit" value="Submit" id="subbutton" disabled> 

我想显示按钮。要显示按钮，我希望我的验证为真，即：

  function checkForm()

  {
  var dessert = document.getElementById("dessert").value;

  if(dessert == "cake"|| dessert == "cookie" || dessert == "icecream"){

当它为真时，我希望启用该按钮。我知道我必须使用 disabled: False 但我将如何为此编写代码行？document.getElementById(残疾人的身份证是什么)？？

Answer 1

function checkForm() { 
    var button = document.getElementById("subbutton");
    var dessert = document.getElementById("dessert").value;
    if(dessert == "cake"|| dessert == "cookie" || dessert == "icecream") {
        button.disabled = undefined;
    }
    else {
        button.disabled = true;
    }
}

示例： http: //jsfiddle.net/3NudE/（有 3 个裸体，哇！）

Answer 2

if(dessert == "cake"|| dessert == "cookie" || dessert == "icecream"){
    {document.getElementById("subbutton").disabled = false;}

http://www.webdeveloper.com/forum/showthread.php?t=147187

Answer 3

function checkForm()
{
   var dessert = document.getElementById("dessert").value;
   document.getElementById("subbutton").disabled = (dessert == "cake"|| dessert == "cookie" || dessert == "icecream");
}