GWT ant devmode:ant is not recognized as an internal or external command

I am following GWT tutorial from co开发者_运维技巧de.google.com. I build an application using webAppCreator & try to run it from command line using ant devmode. It raises this error, ant is not recognized as an internal or external command

Try using the eclipse plugin. You can download eclipse for free by clicking here Then click "help" and "install new software". Enter this link: http://dl.google.com/eclipse/plugin/3.6 Just click next, next and restart eclipse. If you really want to use the command line you should add your sdk path to your computer variables but I don't know the exact setup anymore.