title: display/hide textbox based on drop down list
body: <p>For-example I've got a code:</p>
  
  <pre><code>&lt;form name="myform"&gt;
  &lt;table&gt;
  &lt;td&gt;
  &lt;select name="one" onchange="if (this.selectedIndex=='other'){this.myform['other'].style.visibility='visible'}else {this.myform['other'].style.visibility='hidden'};"&gt;
  &lt;option value="" selected="selected"&gt;Select...&lt;/option&gt;
  &lt;option value="1"&gt;1&lt;/option&gt;
  &lt;option value="2"&gt;3&lt;/option&gt;
  &lt;option value="3"&gt;3&lt;/option&gt;
  &lt;option value="4"&gt;4&lt;/option&gt;
  &lt;option value="5"&gt;5&lt;/option&gt;
  &lt;option value="6"&gt;6&lt;/option&gt;
  &lt;option value="7"&gt;7&lt;/option&gt;
  &lt;option value="other"&gt;Other&lt;/option&gt;
  &lt;/select&gt;
  &lt;input type="textbox" name="other" style="visibility:hidden;"/&gt;
  &lt;/td&gt;
  &lt;/table&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>I need the textbox to appear when option "other" is selected. The above code is not working :(</p>