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try this 

<pre><code class="code-10 nolinks" id="code-125022">&lt;script type=&quot;text/javascript&quot;&gt;
function chnageC (obj)
{
if (obj.options[obj.selectedIndex].value==254){
document.getElementById('statesDiv').style.display='block';
}
else
{
document.getElementById('statesDiv').style.display='none';
}
}
&lt;/script&gt;
&lt;select name=&quot;countries&quot; id=&quot;countries&quot; onchange=&quot;chnageC (this);&quot;&gt;
&lt;option value=&quot;254&quot;&gt;US&lt;/option&gt;
&lt;option value=&quot;090&quot;&gt;Another Country&lt;/option&gt;
&lt;/select&gt;
&lt;div id=&quot;statesDiv&quot; name=&quot;statesDiv&quot; style=&quot;display:none&quot;&gt;
&lt;select name=&quot;states&gt;options go here&lt;/select&gt;&lt;/div&gt;
 
</code></pre>
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<div class="content wysiwyg-content">
I have a select box with the list of countries. When USA (value=254) is selected I want to show another select box with a list of US States, otherwise it should show a text box for user entry. I just need something simple.
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</div>

I have a select box with the list of countries. When USA (value=254) is selected I want to show another select box with a list of US States, otherwise it should show a text box for user entry. I just need something simple.

Select Box onChange option

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