[javascript] Manually type in a value in a "Select" / Drop-down HTML list?

In a Windows Forms application, a drop-down selector list also gives the user the option of typing an alternate value into that same field (assuming the developer has left this option enabled on the control.)

How does one accomplish this in HTML? It appears as if it is only possible to select values from the list.

If it's not possible to do this with straight HTML, is there a way to do this with Javascript?

Telerik also has a combo box control. Essentially, it's a textbox with images that when you click on them reveal a panel with a list of predefined options.

http://demos.telerik.com/aspnet-ajax/combobox/examples/overview/defaultcs.aspx

But this is AJAX, so it may have a larger footprint than you want on your website (since you say it's "HTML").

I love the Shadow Wizard answer, which accually answers the question pretty nicelly. My jQuery twist on this which i use is here. http://jsfiddle.net/UJAe4/

After typing new value, the form is ready to send, just need to handle new values on the back end.

jQuery is:

(function ($) 
{
 $.fn.otherize = function (option_text, texts_placeholder_text) {
    oSel = $(this);
    option_id = oSel.attr('id') + '_other';
    textbox_id = option_id + "_tb";

    this.append("<option value='' id='" + option_id + "' class='otherize' >" + option_text + "</option>");
    this.after("<input type='text' id='" + textbox_id + "' style='display: none; border-bottom: 1px solid black' placeholder='" + texts_placeholder_text + "'/>");
    this.change(

    function () {
        oTbox = oSel.parent().children('#' + textbox_id);
        oSel.children(':selected').hasClass('otherize') ? oTbox.show() : oTbox.hide();
    });

    $("#" + textbox_id).change(

    function () {
        $("#" + option_id).val($("#" + textbox_id).val());
    });
};
}(jQuery));

So you apply this to the below html:

<form>
    <select id="otherize_me">
        <option value=1>option 1</option>
        <option value=2>option 2</option>
        <option value=3>option 3</option>
    </select>
</form>

Just like this:

$(function () {

   $("#otherize_me").otherize("other..", "put new option vallue here");

});

It can be done now with HTML5

See this post here HTML select form with option to enter custom value

<input type="text" list="cars" />
<datalist id="cars">
  <option>Volvo</option>
  <option>Saab</option>
  <option>Mercedes</option>
  <option>Audi</option>
</datalist>

The easiest way to do this is to use jQuery : jQuery UI combobox/autocomplete

ExtJS has a ComboBox control that can do this (and a whole host of other cool stuff!!)

EDIT: Browse all controls etc, here: http://www.sencha.com/products/js/

I faced the same basic problem: trying to combine the functionality of a textbox and a select box which are fundamentally different things in the html spec.

The good news is that selectize.js does exactly this:

Selectize is the hybrid of a textbox and box. It's jQuery-based and it's useful for tagging, contact lists, country selectors, and so on.

Another common solution is adding "Other.." option to the drop down and when selected show text box that is otherwise hidden. Then when submitting the form, assign hidden field value with either the drop down or textbox value and in the server side code check the hidden value.

Example: http://jsfiddle.net/c258Q/

HTML code:

Please select: <form onsubmit="FormSubmit(this);">
<input type="hidden" name="fruit" />
<select name="fruit_ddl" onchange="DropDownChanged(this);">
    <option value="apple">Apple</option>
    <option value="orange">Apricot </option>
    <option value="melon">Peach</option>
    <option value="">Other..</option>
</select> <input type="text" name="fruit_txt" style="display: none;" />
<button type="submit">Submit</button>
</form>

JavaScript:

function DropDownChanged(oDDL) {
    var oTextbox = oDDL.form.elements["fruit_txt"];
    if (oTextbox) {
        oTextbox.style.display = (oDDL.value == "") ? "" : "none";
        if (oDDL.value == "")
            oTextbox.focus();
    }
}

function FormSubmit(oForm) {
    var oHidden = oForm.elements["fruit"];
    var oDDL = oForm.elements["fruit_ddl"];
    var oTextbox = oForm.elements["fruit_txt"];
    if (oHidden && oDDL && oTextbox)
        oHidden.value = (oDDL.value == "") ? oTextbox.value : oDDL.value;
}

And in the server side, read the value of "fruit" from the Request.