I’ve got new information today. After learn create simple wordpress theme, I need find a way to test my theme on various browser including IE6 (the buggy browser), IE7, IE8, FF3, FF3.5, Opera 10, Chrome, and Safari. Based on ebook that I read, the writer suggest me to try adobe browser lab. This free service from adobe will take screenshot how your site look at other browser. Just type the URL and click enter. You will get the screenshot just in a minut. It is very helpful for webdesigner to test their design. To use it, you need to register first.