選擇，比默認值

-3

我怎麼會去提醒用戶另一個選擇他們點擊後提交按鈕可供選擇不要使用Javascript這裏的默認值其他選擇框的選項是我的代碼選擇，比默認值

<select id = "Sel"> 
    <option value ="Song1">default value<br> 
    <option value ="Song2">Break on through<br> 
    <option value ="Song3">Time<br> 
    <option value ="Song4">Money<br> 
    <option value="Song5">Saucerful of Secrets 
</select><br><br>

繼承人我的JavaScript代碼即時通訊不知道從哪裏開始，但這不運行

if(document.getElementByID("Sel").value = "default value") 
{ 
    alert("Pick another option besides default value"); 
}

謝謝！

來源

2012-11-27 Johnny Nguyen

什麼你看起來像迄今爲止的JavaScript？ – jeremy

你的標記不正確。 '

首先，你的標記是不正確的..糾正它作爲

<select id = "Sel"> 
    <option value ="Song1">default value</option> 
    <option value ="Song2">Break on through</option> 
    <option value ="Song3">Time</option> 
    <option value ="Song4">Money</option> 
    <option value="Song5">Saucerful of Secrets</option> 
</select><br><br>

然後在表格提交檢查as

if(document.getElementById('Sel').value=="Song1") 
    return false;

if(document.getElementById('Sel').selectedIndex ==0) 
    return false;

來源

2012-11-27 18:28:40 Rab

您的標記是錯擺在首位。需要關閉開放選項標籤

在改變事件檢查值... 如果value is Song1則警告用戶

HTML

<select id = "Sel"> 
    <option value ="Song1">default value</option> 
    <option value ="Song2">Break on through</option> 
    <option value ="Song3">Time</option> 
    <option value ="Song4">Money</option> 
    <option value="Song5">Saucerful of Secrets</option> 
</select>

的Javascript

var elem = document.getElementById('submit'); 

elem.addEventListener('click', function(){ 
    var selectElem = document.getElementById('Sel'); 
    var val = selectElem.value; 
    if(val == 'Song1'){ 
     alert('Select an option!!'); 
     return false; 
    }   
});

Check Fiddle

來源

2012-11-27 18:27:17

感謝這項工程 –

@JohnnyNguyen ..很高興它的作品:) –

試試這個：

<html> 
    <head> 
     <script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script> 
     <script type="text/javascript"> 
      $(document).ready(function() { 
       $('#Sel').change(function() { 
        if($(this).val()=="Song1"){ 
         alert('bad'); 
        }else{ 
         alert('good'); 
        } 
       }); 
       $('#button-test').click(function() { 
        var bob = $('#Sel').val(); 
        if (bob=='Song1'){ 
         alert('bad'); 
        }else{ 
         alert('good'); 
        } 
       }); 
      }); 
     </script> 
    </head> 
<body> 

<select id = "Sel"> 
    <option value ="Song1">default value</option> 
    <option value ="Song2">Break on through</option> 
    <option value ="Song3">Time</option> 
    <option value ="Song4">Money</option> 
    <option value="Song5">Saucerful of Secrets</option> 
</select><br> 
<br> 
<button id="button-test">

來源

2012-11-27 18:28:20 gibberish

<script> 
    $(document).ready(function() { 
     $("#Sel").live('click', function (event) { 
     var myval=$(this).val; 
     alert(myval); 
     }); 
    </script> 
    <select id = "Sel"> 
      <option name="opSel" value ="Song1">default value</option> 
      <option name="opSel" value ="Song2">Break on through</option> 
      <option name="opSel" value ="Song3">Time</option> 
      <option name="opSel" value ="Song4">Money</option> 
      <option name="opSel" value="Song5">Saucerful of Secrets</option> 
     </select>

來源

2012-11-27 18:29:16 Daniel

選擇，比默認值

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