Set kind of user derived type at runtime

I am trying to figure out the correct methodology for setting a user derived type variable at runtime based on some user input.  The following would be a very simply example of two user derived types: One and Two.

type One
   integer :: ivalue=0
end type One

type Two
   integer :: ivalue=0
end type Two

How would I go about setting a variable,x, to a specific user derived type based on user input.  Pseudocode would be something along the lines of

if userinput = 1, then set x to type One

elseif userinput =2, then set x to type Two