function displayPrevious(current, list){

	list = list.split(',');
	var previous = 0;
	var somethingDisplayed = false;

	for(i=0;i<list.length;i++){
		if(somethingDisplayed == false){
			previous = i-1;
			$("#visu-left-" + list[i]).css("display", "none");
			if(list[i]==current && previous>=0){
				somethingDisplayed = true;
				$("#visu-left-" + list[previous]).css("display", "block");
			}
		}
	}

	if(somethingDisplayed == false){
			$("#visu-left-" + current).css("display", "block");
	}

	return false;
}

function displayNext(current, list){

	list = list.split(',');
	var next = 0;
	var somethingDisplayed = false;

	for(i=0;i<list.length;i++){
		if(somethingDisplayed == false){
			next = i+1;
			$("#visu-left-" + list[i]).css("display", "none");
			if(list[i]==current && next<list.length){
				somethingDisplayed = true;
				$("#visu-left-" + list[next]).css("display", "block");
			}
		}
	}


	if(somethingDisplayed == false){
			$("#visu-left-" + current).css("display", "block");
	}

	return false;
}