[R] Error msg in rpanel

I am working on the r panel package. Now if i have a function that uses a radiogroup button, and if i attempt to run the function from inside the rpanel menu, i get this error: Error in panel$intname : $ operator is invalid for atomic vectors However if i run the function per se i.e. not from

Re: [R] Error msg in rpanel

If I run the whole code and click on the addition menu and then click Add, the error comes. But not when I just call add(). So I guess the problem is not with the rpanel package. Also tried panel[vars] instead of panel$vars. no luck. Same error when I call the add function from the rpanel GUI.