How can I use a function created by dfittool?

I created a function for a pdf and normal fit on the dfittool, however, I am not able to call it from my code.

this is the function header:

function pd1 = createFit(LT_k)

and this is how I am calling it

x = createFit(LT_k)

what am I doing wrong?

[Steven Lord]

What happens when you call it? Do you receive an error or a warning (and if so, what is the FULL text of the error or warning message?) Does it give you a different result than you expect?