[javascript] Validate select box

I'm using the jQuery plugin Validation to validate a form. I have a select list looking like this:

<select id="select">
<option value="">Choose an option</option>
<option value="option1">Option1</option>
<option value="option2">Option2</option>
<option value="option3">Option3</option>
</select>

Now, I want to make sure that the user selects anything but "Choose an option" (which is the default one). So that it won't validate if you choose the first option. How can this be done?

Perhaps there is a shorter way but this works for me.

<script language='JavaScript' type='text/javascript'>
    function validateThisFrom(thisForm) {
        if (thisForm.FIELDNAME.value == "") {
            alert("Please make a selection");
            thisForm.FIELDNAME.focus();
            return false;
        }
        if (thisForm.FIELDNAME2.value == "") {
            alert("Please make a selection");
            thisForm.FIELDNAME2.focus();
            return false;
        }
    }
</script>
<form onSubmit="return validateThisFrom (this);">
    <select name="FIELDNAME" class="form-control">
        <option value="">- select -</option>
        <option value="value 1">Visible info of Value 1</option>
        <option value="value 2">Visible info of Value 2</option>
    </select>
    <select name="FIELDNAME2" class="form-control">
        <option value="">- select -</option>
        <option value="value 1">Visible info of Value 1</option>
        <option value="value 2">Visible info of Value 2</option>
    </select>
</form>

if (select == "") {
    alert("Please select a selection");
    return false;

That should work for you. It just did for me.

I don't know how was the plugin the time the question was asked (2009), but I faced the same problem today and solved it this way:

1. Give your select tag a name attribute. For example in this case

   <select name="myselect">

2. Instead of working with the attribute value="default" in the tag option, disable the default option as suggested by Jeremy Visser or set value=""

   <option disabled="disabled">Choose...</option>

   or

   <option value="">Choose...</option>

3. Set the plugin validation rule

   $( "#YOUR_FORM_ID" ).validate({ rules: { myselect: { required: true } } });

   or

   <select name="myselect" class="required">

Obs: redsquare's solution works only if you have just one select in your form. If you want his solution to work with more than one select add a name attribute to your select.

Hope it helps! :)

   <script type="text/JavaScript">  
function validate() 
{
if( document.form1.quali.value == "-1" )
   {
     alert( "Please select qualification!" );
     return false;
   }
}

</script>
<form name="form1" method="post" action="" onsubmit="return validate(this);">
<select name="quali" id="quali" ">
        <option value="-1" selected="selected">select</option>
        <option value="1">Graduate</option>
        <option value="2">Post Graduate</option>
      </select> 
</form>





// this code works 110% tested by me after many complex jquery method validation but it is simple javascript method plz try this if u fail in drop down required validation//

<select id='bookcategory' class="form-control" required="">
                    <option value="" disabled="disabled">Category</option>
                    <option value="1">LITERATURE & FICTION</option>
                    <option value="2">NON FICTION</option>
                    <option value="3">ACADEMIC</option>
            <option value="4">CHILDREN & TEENS</option>

                </select>

HTML form validation can be performed automatically by the browser. Try the above code:
The rest all will be done automatically, no need to create any js functions just this dropdown and a submit button.

you want to make sure that the user selects anything but "Choose an option" (which is the default one). So that it won't validate if you choose the first option. How can this be done?

You can do this by simple adding attribute required = "required" in the select tag. you can see it in below code

<select id="select" required="required">
<option value="">Choose an option</option>
<option value="option1">Option1</option>
<option value="option2">Option2</option>
<option value="option3">Option3</option>
</select>

It worked fine for me at chorme, firefox and internet explorer. Thanks

For starters, you can "disable" the option from being selected accidentally by users:

<option value="" disabled="disabled">Choose an option</option>

Then, inside your JavaScript event (doesn't matter whether it is jQuery or JavaScript), for your form to validate whether it is set, do:

select = document.getElementById('select'); // or in jQuery use: select = this;
if (select.value) {
  // value is set to a valid option, so submit form
  return true;
}
return false;

Or something to that effect.