var theImg;

var defaultCaption = 'captions/default.png';
var captions = [
	['home', 'captions/default.png'],
	['articles', 'captions/articles.png'],
	['blogs', 'captions/blogs.png'],
	['forums', 'captions/forums.png'],
	['photos', 'captions/photos.png'],
	['about', 'captions/about.png']
];

function captionInit()
{
	theImg = document.getElementById('caption');
	
	// Setup events and preload
	for (var i = 0; i < captions.length; i++)
	{
		addEvent(document.getElementById('link-' + captions[i][0]), 'mouseover', captionOn);
		addEvent(document.getElementById('link-' + captions[i][0]), 'mouseout', captionOff);
		var img = new Image();
		img.src = captions[i][1];
		captions[i][1].img = img;
	}
}

function captionOn()
{
	var captionId = this.id.split('-')[1];
	for (var i = 0; i < captions.length; i++)
	{
		if (captions[i][0] == captionId)
		{
			theImg.src = captions[i][1];
			break;
		}
	}
}

function captionOff()
{
	theImg.src = defaultCaption;
}

addEvent(window, 'load', captionInit);