/*class slide*/
function Slide( ThumbnailURL, MainPicureURL )

{

	this.ThumbnailURL = ThumbnailURL;

	this.MainPictureURL = MainPicureURL;

}


/*class slideshow*/
function SlideShow()

{	

	this._IndexOfLeftmostShowingThumbnail = 0;

	this._SlideList = new Array();

	

	this.NumberOfShowingThumbnails = 3;

	

	this.addSlide = SlideShow_AddSlide;

	this.canScrollNextThumbnail = SlideShow_CanScrollNextThumbnail;

	this.scrollNextThumbnail = SlideShow_ScrollNextThumbnail;

	this.canScrollPreviousThumbnail = Slideshow_CanScrollPreviousThumbnail;

	this.scrollPreviousThumbnail = Slideshow_ScrollPreviousThumbnail;

	this.selectSlide = Slideshow_SelectSlide;

	this.refreshThumbnails = Slideshow_RefreshThumbnails;	

}



function SlideShow_AddSlide( Slide )

{	

	this._SlideList.push( Slide );	

}



function SlideShow_ScrollNextThumbnail()

{

	if ( this.canScrollNextThumbnail() )

	{

		this._IndexOfLeftmostShowingThumbnail++;

		this.refreshThumbnails();

	}

}



function Slideshow_ScrollPreviousThumbnail()

{

	if ( this.canScrollPreviousThumbnail() )

	{

		this._IndexOfLeftmostShowingThumbnail--;

		this.refreshThumbnails();

	}

}



function SlideShow_CanScrollNextThumbnail()

{

	var CanScrollNextThumbnail = false;



	if ( (this._IndexOfLeftmostShowingThumbnail + this.NumberOfShowingThumbnails)  < this._SlideList.length )

	{

		CanScrollNextThumbnail = true;

	}

	

	return CanScrollNextThumbnail;		

}



function Slideshow_CanScrollPreviousThumbnail()

{

	var CanScrollPreviousThumbnail = false;

	if ( this._IndexOfLeftmostShowingThumbnail > 0 )

	{

		CanScrollPreviousThumbnail = true;

	}

	

	return CanScrollPreviousThumbnail;

}



function Slideshow_SelectSlide( ShowingIndex )

{

	var IndexInSlideList = this._IndexOfLeftmostShowingThumbnail + ShowingIndex;

	var SlideToSelect = this._SlideList[ IndexInSlideList ];

	var MainPicture = window.document.getElementById( "main-picture" );

	MainPicture.src = SlideToSelect.MainPictureURL;	

}



function Slideshow_RefreshThumbnails()

{

	for ( var i = 0; i < this.NumberOfShowingThumbnails; ++i )

	{		

		var ThumbnailID = "thumbnail-" + ( i + 1 );

		var Thumbnail = window.document.getElementById( ThumbnailID );

		var ThumbnailURL = this._SlideList[ this._IndexOfLeftmostShowingThumbnail + i ].ThumbnailURL;

		Thumbnail.src = ThumbnailURL;

	}		

}