How to input double in simulink + sfunction

Hi, I want to create a block where user can input data into simulink in order to run the program. But i don't know how to do that part and if i want to do so, do i need to make any changes in my s-function?

Also i have been trying to create s-function but it doesn't work out. It has given me this error: Undefined function 'sfunction.m' for input arguments of type 'Simulink.MSFcnRunTimeBlock'. Can anyone plz tell me what it is. This is my first time working on s-function and it is very confusing.

Thank you for your help.

[Kaustubha Govind]

First, it's not clear that you need an S-function here. Do you need the user to enter an input at every time-step in the simulation, or up-front at the beginning of simulation? Only use an S-function if you want the former.