选择，比默认值

-3

我怎么会去提醒用户另一个选择他们点击后提交按钮可供选择不要使用Javascript这里的默认值其他选择框的选项是我的代码选择，比默认值

<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>

继承人我的JavaScript代码即时通讯不知道从哪里开始，但这不运行

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

谢谢！

来源

2012-11-27 Johnny Nguyen

什么你看起来像迄今为止的JavaScript？ – jeremy

你的标记不正确。 '

首先，你的标记是不正确的..纠正它作为

<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>

然后在表格提交检查as

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

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

来源

2012-11-27 18:28:40 Rab

您的标记是错摆在首位。需要关闭开放选项标签

在改变事件检查值... 如果value is Song1则警告用户

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

来源

2012-11-27 18:27:17

感谢这项工程 –

@JohnnyNguyen ..很高兴它的作品:) –

试试这个：

<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">

来源

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>

来源

2012-11-27 18:29:16 Daniel

选择，比默认值

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