function nextpage() {
						if(clip==aantal) { document.location.href=video[1]+".php"; }
						else {document.location.href=video[clip+1]+".php"; }
					}
		
function prevpage() {
						if(clip==1) { document.location.href=video[aantal]+".php"; }
						else {document.location.href=video[clip-1]+".php"; }
					}

function back_videobook() {
						document.location.href="videobook.php#"+video[clip];
						  }