Simple WordPress Post Thumbnails with Regular Expressions

// get post content
	global $post;
	$content = $post->post_content;
 
	// set default image value
	$theImageSrc = '';
 
	// regex to find all images
	preg_match_all ('|<img .*?src=[\'"](.*?)[\'"].*?/>|i', $content, $matches);
 
	$imageCount = count ($matches);
 
	// needs to be a loop
	// Notice the += 2 in the for iterator
	// 0 = full image html tag
	// 1 = image path selected
	if ($imageCount >= 1) {
		for ($i = 1; $i <= $imageCount; $i += 2) {
			if (isset ($matches[$i][0])) {
				$theImageSrc = $matches[$i][0];
				break;
			}
		}
	}