Combobox - Seleziona un tipo di item

<table>
        <tr><td>
        <label for="check_letter">Enter a letter: </label><input type="text" name="check_letter" size="1">
        </td></tr>
        <tr><td>
        <label for="matching_words"><input type="button" name="matching_words" value="Select ALL matching Words" onclick="set_matching_words(this.form.letters, this.form.check_letter);"></label>
        </td></tr>
        <tr><td>
        <label for="letters">Matching Word: </label><select name="letters" multiple='multiple' size="5">
          <option value="apple">apple</option>
          <option value="ant">ant</option>
          <option value="ape">ape</option>
          <option value="age">age</option>
          <option value="boy">boy</option>
          <option value="banana">banana</option>
          <option value="carrot">carrot</option>
          <option value="cat">cat</option>
          <option value="daisy">daisy</option>
          <option value="desk">desk</option>
          <option value="elephant">elephant</option>
          <option value="eagle">eagle</option>
          <option value="fox">fox</option>
          <option value="fat">fat</option>
          <option value="goat">goat</option>
          <option value="good">good</option>
          <option value="gum">gum</option>
          <option value="hut">hut</option>
          <option value="hop">hop</option>
          <option value="insect">insect</option>
          <option value="ice">ice</option>
          <option value="jump">jump</option>
          <option value="kite">kite</option>
          <option value="lamp">lamp</option>
          <option value="lap">lap</option>
          <option value="monkey">monkey</option>
          <option value="mat">mat</option>
          <option value="nature">nature</option>
          <option value="nose">nose</option>
          <option value="owl">owl</option>
          <option value="pocket">pocket</option>
          <option value="pick">pick</option>
          <option value="quote">quote</option>
          <option value="rabbit">rabbit</option>
          <option value="run">run</option>
          <option value="soft">soft</option>
          <option value="sit">sit</option>
          <option value="table">table</option>
          <option value="toy">toy</option>
          <option value="understand">understand</option>
          <option value="vote">vote</option>
          <option value="winter">winter</option>
          <option value="xmas">xmas</option>
          <option value="yes">yes</option>
          <option value="zoo">zoo</option>
        </select>
        </td></tr>
        </table>
        </form>

<h2>The code</h2>
    <p>
    <code>
        function set_matching_words(selectObj, txtObj) {<br>
          var letter = txtObj.value;<br>
          <br>
          for(var i = 0; i < selectObj.length; i++) {<br>
             if(selectObj.options[i].value.charAt(0) == letter) {<br>
                selectObj.options[i].selected = true;<br>
             } else {<br>
                selectObj.options[i].selected = false;<br>
             }<br>
          }<br>
        <br>
        }<br>
    </code>
    </p>

<p>
Download the code here: <a href="javascript-form-value-multi-select-example.zip"
>javascript-form-field-example-3.zip</a>
</p>

<p>
<a href="../../javascript-form/javascript-form-value-select.phtml">Back to article: set a form field using Javascript</a>
</p>
</body>
</html>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns='http://www.w3.org/1999/xhtml'>
<head>
<title>Setting the values of a (multiple)select form element using JavaScript</title>
<link rel="stylesheet" type="text/css" href="/style/jsc.css">
</head>
<body>
<h1>Setting the values of a (multiple)select form element using javascript</h1>
<I>[Hint: enter a letter and press the 'Select ALL matching Words' button]</I>
<p>Word Finder</p>

<form name="check_letter_frm" action="#">

<table>
<tr><td>
<label for="check_letter">Enter a letter: </label><input type="text" name="check_letter" size="1">
</td></tr>
<tr><td>
<label for="matching_words"><input type="button" name="matching_words" value="Select ALL matching Words" onclick="set_matching_words(this.form.letters, this.form.check_letter);"></label>
</td></tr>
<tr><td>
<label for="letters">Matching Word: </label><select name="letters" multiple='multiple' size="5">
<option value="apple">apple</option>
<option value="ant">ant</option>
<option value="ape">ape</option>
<option value="age">age</option>
<option value="boy">boy</option>
<option value="banana">banana</option>
<option value="carrot">carrot</option>
<option value="cat">cat</option>
<option value="daisy">daisy</option>
<option value="desk">desk</option>
<option value="elephant">elephant</option>
<option value="eagle">eagle</option>
<option value="fox">fox</option>
<option value="fat">fat</option>
<option value="goat">goat</option>
<option value="good">good</option>
<option value="gum">gum</option>
<option value="hut">hut</option>
<option value="hop">hop</option>
<option value="insect">insect</option>
<option value="ice">ice</option>
<option value="jump">jump</option>
<option value="kite">kite</option>
<option value="lamp">lamp</option>
<option value="lap">lap</option>
<option value="monkey">monkey</option>
<option value="mat">mat</option>
<option value="nature">nature</option>
<option value="nose">nose</option>
<option value="owl">owl</option>
<option value="pocket">pocket</option>
<option value="pick">pick</option>
<option value="quote">quote</option>
<option value="rabbit">rabbit</option>
<option value="run">run</option>
<option value="soft">soft</option>
<option value="sit">sit</option>
<option value="table">table</option>
<option value="toy">toy</option>
<option value="understand">understand</option>
<option value="vote">vote</option>
<option value="winter">winter</option>
<option value="xmas">xmas</option>
<option value="yes">yes</option>
<option value="zoo">zoo</option>
</select>
</td></tr>
</table>
</form>

<h2>The code</h2>
<p>
<code>
function set_matching_words(selectObj, txtObj) {<br>
var letter = txtObj.value;<br>
<br>
for(var i = 0; i < selectObj.length; i++) {<br>
if(selectObj.options[i].value.charAt(0) == letter) {<br>
selectObj.options[i].selected = true;<br>
} else {<br>
selectObj.options[i].selected = false;<br>
}<br>
}<br>
<br>
}<br>
</code>
</p>

<p>
Download the code here: <a href="javascript-form-value-multi-select-example.zip"
>javascript-form-field-example-3.zip</a>
</p>

<p>
<a href="../../javascript-form/javascript-form-value-select.phtml">Back to article: set a form field using Javascript</a>
</p>
</body>
</html>