如果用户点击提交按钮从默认值以外的选择框中选择一个选项,使用javascript这里是我的代码,我将如何提醒用户
<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代码我不确定从哪里开始,但这不会运行
if(document.getElementByID("Sel").value = "default value")
{
alert("Pick another option besides default value");
}
谢谢!
答案 0 :(得分:0)
您的标记首先是错误的。需要关闭打开选项标记
在更改事件中检查值...
如果value is Song1
,则提醒用户
<强> HTML 强>
<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>
<强>的Javascript 强>
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;
}
});
<强> Check Fiddle 强>
答案 1 :(得分:0)
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">
答案 2 :(得分:0)
首先,您的标记不正确..将其更正为
<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>
然后在表单提交检查
if(document.getElementById('Sel').value=="Song1")
return false;
OR
if(document.getElementById('Sel').selectedIndex ==0)
return false;
答案 3 :(得分:0)
<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>