how to do this effect in javascript?
<p>the effect map is <a href="http://phplist.xxmn.com/1.jpg" rel="nofollow">http://phplist.xxmn.com/1.jpg</a></p>

<p>There are two searches engines. one is the site's default search. another is the google custom search. When the vistor choses the site's default search, it should use the site's default search. When they chose the google custom search option, it should use the google custom search.</p>

<p>the html code :</p>

<pre><code>   &lt;select class="search_l" &gt;
        &lt;option value="0"&gt;the default search&lt;/option&gt;
         &lt;option value="1"&gt;google search&lt;/option&gt;
      &lt;/select&gt;

 &lt;form action="/"  accept-charset="UTF-8" method="post" id="search-theme-form"&gt; 
 &lt;div&gt;&lt;div id="search" class="container-inline"&gt; 
 &lt;div class="form-item" id="edit-search-theme-form-1-wrapper"&gt; 
 &lt;input type="text" maxlength="128" name="search_theme_form" id="edit-search-theme-form-1" size="15" value="" title="put the search keyword in" class="form-text" /&gt; 
&lt;/div&gt; 
&lt;input type="image" name="submit" id="edit-submit"  class="form-submit"    src="images/search_btn_top.gif" /&gt; 
&lt;input type="hidden" name="form_build_id" id="form-2" value="form-f02"  /&gt; 
&lt;input type="hidden" name="form_token" id="edit-search-theme-form-form-token" value="c5a"  /&gt; 
 &lt;input type="hidden" name="form_id" id="edit-search-theme-form" value="search_theme_form"  /&gt; 
</code></pre>

<p> 
 
</p>

<p>This is the site's default search. I have added a select dropdown option to it. But I don't know how to use both. When i chose the google search, it should use google search and when I choose the default search it should use the default search.</p>
