var ids = ['tool_zoom', 'tool_pencil', 'tool_eraser'];
for (var i = 0; i < ids.length; i++) {
var div = document.getElementById(ids[i]);
var ids = ['tool_zoom', 'tool_pencil', 'tool_eraser'];
for (var i = 0; i < ids.length; i++) {
var div = document.getElementById(ids[i]);