function changeImage(filename,imgname)
	{
		if (imgname == 'mainimage1')
			document.mainimage1.src = filename;
		else if (imgname == 'mainimage2')
			document.mainimage2.src = filename;
		else if (imgname == 'mainimage3')
			document.mainimage3.src = filename;
		else if (imgname == 'mainimage4')
			document.mainimage4.src = filename;
		else if (imgname == 'mainimage5')
			document.mainimage5.src = filename;
	}