function roll(imgName, funct) { 
        switch(funct) { 
                case 'over': 
                        eval('document.images["' + imgName + '"].src="images/' + imgName + '-ov.gif"'); 
                        break; 
                case 'out': 
                        eval('document.images["' + imgName + '"].src="images/' + imgName + '-in.gif"'); 
                        break; 
                case 'initial': 
                        eval('document.images["' + imgName + '"].src="images/' + imgName + '-in.gif"'); 
                        break; 
                default: 
                        break; 
        } 
}