禁用或啓用單選按鈕的Javascript

Question

我正在嘗試做一些比這更復雜的事情，但我把它分解並扔到JSFIDDLE，我仍然無法使它工作。

有什麼建議嗎？

JSFiddle

HTML：

<label for="service-type">Value</label> 
<select id="service-type" onChange="hamburger()"> 
    <option>0</option> 
    <option>1</option> 
    <option>2</option> 
    <option>3</option> 
</select> 
<label for="receiptNo">No</label> 
<input type="radio" name="receipt" id="receiptNo"> 
<label for="receiptYes">Yes</label> 
<input type="radio" name="receipt" id="receiptYes"> 

的Javascript：

var e = document.getElementById("service-type"); 
var ServiceUser = e.options[e.selectedIndex].text; 

function hamburger() { 
    if (ServiceUser.value === "2") { 
     document.getElementById("receiptNo").disabled = true; 
     document.getElementById("receiptYes").checked = true; 
    } 
} 

Answer 1

發送函數調用器的詳細信息，這樣

​​

完成它的Wi th javascript

<script type="text/javascript"> 
    function hamburger(sender) { // sender here has all details of dropdown 
     if (sender.value === "2") { 
      document.getElementById("receiptNo").disabled = true; 
      document.getElementById("receiptYes").checked = true; 
     } 
    } 
</script>