public function compare( $fromtitle = null, $fromid = null, $fromrev = null, $totitle = null, $toid = null, $torev = null ) {

		pecho( "Getting differences...\n\n", PECHO_NORMAL );
		$apiArray = array(
			'action' => 'compare'
		);
		if( !is_null( $fromrev ) ) {
			$apiArray['fromrev'] = $fromrev;
		} else {
			if( !is_null( $fromid ) ) {
				$apiArray['fromid'] = $fromid;
			} else {
				if( !is_null( $fromtitle ) ) {
					$apiArray['fromtitle'] = $fromtitle;
				} else {
					pecho( "Error: a from parameter must be specified.\n\n", PECHO_FATAL );
					return false;
				}
			}
		}
		if( !is_null( $torev ) ) {
			$apiArray['torev'] = $torev;
		} else {
			if( !is_null( $toid ) ) {
				$apiArray['toid'] = $toid;
			} else {
				if( !is_null( $totitle ) ) {
					$apiArray['totitle'] = $totitle;
				} else {
					pecho( "Error: a to parameter must be specified.\n\n", PECHO_FATAL );
					return false;
				}
			}
		}
		$results = $this->apiQuery( $apiArray );

		if( isset( $results['compare']['*'] ) ) {
			return $results['compare']['*'];
		} else {
			pecho( "Compare failure... Please check your parameters.\n\n", PECHO_FATAL );
			return false;
		}
	}