custom built transfer function block in simulink

I want to create a block of transfer function "2s+1" in Simulink.When I try to add ,by editing 1/s+1,could edit numerator for 2s+1 but recieve error message on editing denominator value to 1.Please guide how to proceed.Also,please help me to know,if a transfer function created in matlab by code,can it be converted to the respective block in .mdl file,by any way?

Answer 1

[Guy Rouleau]

After you open the block dialog, click on the "Help" button... it should explain everything.

You can find the same here:

http://www.mathworks.com/help/toolbox/simulink/slref/transferfcn.html

Answer 2

[Kaustubha Govind]

The "s" is a derivative term, so why not just use the Derivative block, followed by a Gain=2, and add that output back to the input to get "2s+1".