如何在“onchange”事件上将链接与<select> <option>值连接起来

<?php echo $this->getUrl(); ?> gives me my index page url .i.e. www.domain.com/index.php/

But now, what I want is, when any particular option is selected, it should add to this url. .e.g.

www.domain.com/index.php/wordpress/

I write this code for it but now don know how to get it done. :(

<select onchange="setLocation('<?php echo $this->getUrl(); ?>')">
     <option value="">&nbsp;</option>
     <option value="wordpress">Wordpress</option>
     <option value="drupal">drupal</option>
     <option value="magento">Megento</option>
</select>

Also, I had searched this link but couldn't take help from it. As it didnt work for me.

<select name="forma" ONCHANGE="location = this.options[this.selectedIndex].value;">
 <option value="Home">Home</option>
 <option value="Contact">Contact</option>
 <option value="Sitemap">Sitemap</option>
</select>

With this (note that I've added this as the first argument):

<select onchange="setLocation(this, '<?php echo $this->getUrl(); ?>')">
     <option value="">&nbsp;</option>
     <option value="wordpress">Wordpress</option>
     <option value="drupal">drupal</option>
     <option value="magento">Megento</option>
</select>

You could write the following JS:

function setLocation(elm, baseUrl) {
    var keyword = elm.options[elm.selectedIndex].value; // Gets the selected keyword (some sanity check could be done)
    window.location = 'http://' + baseUrl + keyword + '/'; // Redirects
}

Alternatively:

<select name="forma" onchange="window.location='http://<?php echo $this->getUrl(); ?>' + this.options[this.selectedIndex].value + '/';">
 <option value="Home">Home</option>
 <option value="Contact">Contact</option>
 <option value="Sitemap">Sitemap</option>
</select>

(EDIT Prepended http:// to both examples.)