macOS Execute commands as a root through a widget

[DSerafim]

I am working on a widget and need to execute a command as root. I followed the next tutorial: http://www.oreillynet.com/mac/blog/2006/07/giving_your_widget_that_sudo_v_1.html
But I cannot make it work. When root label would be appear, instead appear undefined label. Anyone know another new tutorial?