title: hidden/show the text field when select dropdown list specified value
body: <p>I start to generate my script from this solution find at this link <a href="https://stackoverflow.com/questions/12158737/display-hide-textbox-based-on-drop-down-list">display/hide textbox based on drop down list</a></p>
  
  <p>In this case, the value must be a character value. But in my situation I need to value is a ID number specified get from mysql database.</p>
  
  <p>This is my modified script and not work. When select the Other value, not display the textbox.</p>
  
  <pre><code>&lt;form name="myform"&gt;
      &lt;table&gt;
          &lt;tr&gt;
              &lt;td&gt;
                  &lt;select name="one" onchange="if (this.value=='10000'){this.form['10000'].style.visibility='visible'}else {this.form['10000'].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="10000"&gt;Other&lt;/option&gt;
                  &lt;/select&gt;
                  &lt;input type="textbox" name="10000" style="visibility:hidden;"/&gt;
              &lt;/td&gt;
          &lt;/tr&gt;
      &lt;/table&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>But this script workfine if change the value 10000 to OtherValue word.
  How to modify this script?</p>