Wordpress custom fields...

I am using this code then using the custom field to embed the videos...

<div id="videoblock">
<?php $key="videoembed"; echo get_post_meta($post->ID, $key, true); ?><P/>
</div>

Then in the custom field I use videoembed and then put a embed video code under value. It works find but I am trying to do something a bit more involved. I would like to have multiple videoembed area such as $key="videoembed1" , $key="videoembed2" etc.. so I can embed the same video but from multiple sources. I would then like to have a drop down menu where you can select which video to call, which will then display the video in the videoblock div. Does anyone have any idea how I can do that?

Thanks in advance.