How can I store a class I want to send a message to in a variable?

Right now, my game is set up with a manager class, and a UI, Utility, Sound and Game class which come off of the manager class. For my button script, there are 2 variables -
Message, containing the message.
SendTo, containing a string which changes what to send it to.

I do not want to keep the SendTo, and want to instead store the class I want to send to directly in the variable. This way I can add new classes, and also send messages to many other gameobjects.

Help would be great, thanks !

void OnMouseDown(){
if(SendTo == "UI"){
Manager.UI.SendMessage(message);
}
if(SendTo == "Game"){
Manager.Game.SendMessage(message);
}
if(SendTo == "Utility"){
Manager.Utility.SendMessage(message);
}
if(SendTo == "Sound"){
Manager.Sound.SendMessage(message);
}
leaving = true;
}

 

Oh, thanks! That's alot simpler than what I was trying to do after posting this, thank you!