Formula in SQL Enterprise manager

I have a table with 2 columns and I want to have a 3rd column that combines the 1st and 2nd column automatically and populates the 3rd column.

i know this can be done with the Formula option in the 3rd column but I dont know how to combine columns. One is of datatype int and the other is of datatype varchar.

Here are my column names etc.

name var
-------
step int
action varchar

thankscast the int as a varchar and concatenate them both together in an update statement