List Video Attachment

I would like to able to list the latest video attachment uploaded to a post, wrapped in an if/else statement so that if no video has been uploaded no link is displayed.

How would I go about getting a video attachment link from the post I am currently viewing.

I have done this with images by using the following in functions.php

<?php
function postimage($size=medium) {
	if ( $images = get_children(array(
		'post_parent' => get_the_ID(),
		'post_type' => 'attachment',
		'numberposts' => 1,
		'post_mime_type' => 'image',)))
	{
		foreach( $images as $image ) {
			$attachmenturl=wp_get_attachment_url($image->ID);
			$attachmentimage=wp_get_attachment_image( $image->ID, $size );

			echo $attachmentimage;
		}
	} else {
		echo "";
	}
}
?>

and then using

<?php postimage('thumbnail'); ?>

where i want to show the image. Is there something similar for video attachments or could I modify or add to the above code and if so how.

Thanks in advance.