

That is to say that, by default, gksu and gksudo behave exactly the same. The default behavior of gksu in Ubuntu is to act as a frontend for sudo, not for su. gksu can be configured to use either sudo or su as its backend.The cause of your problem, and the reason most of the other answers so far don't work (with the exception of Marty Fried's excellent answer), is: normaluser knows admin's password and has (presumably) been told s/he may use it for this purpose.

anyapplication is the name of the graphical application normaluser wants to run as root.(Of course, any graphical commands should use a graphical frontend like gksu/ gksudo, and not sudo directly.) admin is an administrator who can run commands as root with sudo.normaluser is a normal user who is not an administrator and cannot run commands as root with sudo.
