var currentImageNumber = 6;
var rotate;

function rotateImage()
{
    
    var nextImageNumber = currentImageNumber + 1;
    if(nextImageNumber == 7)
        nextImageNumber = 1;
        
    var currentImage = 'image_' + currentImageNumber;
    var nextImage = 'image_' + nextImageNumber;
    
	if($(currentImage).fx){$(currentImage).fx.stop();}
	if($(nextImage).fx){$(nextImage).fx.stop();}
	$(currentImage).fx = $(currentImage).effect('opacity', {duration: 2000}).start(0);
	$(nextImage).fx = $(nextImage).effect('opacity', {duration: 2000}).start(1);
	currentImageNumber = nextImageNumber;
}

function viewImage(number)
{
    if(number != currentImageNumber)
    {
        var nextImage = 'image_' + number;
        var currentImage = 'image_' + currentImageNumber;
        
	    if($(currentImage).fx){$(currentImage).fx.stop();}
	    if($(nextImage).fx){$(nextImage).fx.stop();}
	    $(currentImage).fx = $(currentImage).effect('opacity', {duration: 2000}).start(0);
	    $(nextImage).fx = $(nextImage).effect('opacity', {duration: 2000}).start(1);
    	
	    currentImageNumber = number;
	    $clear(rotate);
	}
}

function startImageRotation(t)
{
    if( document.getElementById('image_' + currentImageNumber) != null)
        rotate = (function(){rotateImage()}).periodical(t);
}