If statements that search to see if there are certain characters in them. c++

I am trying to write two if statements that will search for a certain character within a string or verify if a character is a specific letter.

One has to verify if the information being passed is an 's' or an 'h' and if its not, set it to an 's'.

the other has to verify if a name has a comma in it. The data is passed in Last, First format and if its missing the comma, it will set it to "unknown"

Help on getting started with this? C++