/* ImageRollover.js */
_aImages = new Array( 0 );


function ImageRollover()
{
	/* private memebers */
	
	
	/* public interface */
	this.preloadImage = _preloadImage;
	this.swapImage = _swapImage;
	
	/* implementation */
	
	function _preloadImage( sKey, sImage, sImageRoll, iWidth, iHeight )
	{
		len = _aImages.length;
		_aImages[len] = new Array( sKey, new Image( iWidth, iHeight ), new Image( iWidth, iHeight ) );
		_aImages[len][1].src = sImage;
		_aImages[len][2].src = sImageRoll;
		return( this );
	}

	function _swapImage( sKey, sState )
	{
		document.images[sKey].src = getImage( sKey, (sState == 'on') ? 1 : 2 ).src;
	}
}

function getImage( sKey, iIndex )
{
	for(i = 0; i < _aImages.length; ++i)
	{
		if(_aImages[i][0].toString() == sKey.toString())
		{	
			return( _aImages[i][iIndex] );
		}
	}
}