Compare two version numbers in php.

version_compare.php

	/**
	 * Determine if this asset needs to be updated.
	 * 
	 * @return boolean Returns TRUE of the local version number
	 * is lower than the remote version number, else FALSE.
	 */
	function needs_update() {

		$old_version = $this -> old_version;

		$new_version = $this -> new_version;

		$compare = version_compare( $old_version, $new_version );

		if( $compare == -1 ) { return TRUE; }

		return FALSE;

	}