Aptana how to active preview

how to activate the live preview in Aptana? in its daownload page says: “Live Preview Quickly switch between a view开发者_开发知识库 of your source code and the rendered HTML page in popular web browsers. ” but how?

To preview an html file, first open the html file and then click on the preview icon on the toolbar:

I am not completely sure, but I think you can simply click the green "run" button. Here is a link to the documentation about "previewing": http://wiki.appcelerator.org/display/tis/Previewing+a+project+in+a+web+browser