 some slides).";
								alert(message);
							}
							callback( timings );
						} );
					} );

				}

				/**
				 * Return the number of seconds allocated for presenting
				 * all slides up to and including this one.
				 */
				function getTimeAllocated( timings, callback ) {

					callRevealApi( 'getSlidePastCount', [], function ( currentSlide ) {
						var allocated = 0;
						for (var i in timings.slice(0, currentSlide + 1)) {
							allocated += timings[i];
						}
						callback( allocated );
	