var input = "H.E,L:;!?L()[o]{}";

    var str = input.toLowerCase().replace(/[.,:;!?(){}\[\]]+/g, '');

    var result;

    switch(str){    

        case "hi": result = "Hi there!";break;

        case "hello": result = "Hello,hello!";break;

        case "good morning": result = "Good morning, pal!";break;

        case "good evening": result = "Good evening, sir!";break;

        default:

        result = "I don't know what to say. Try to say 'hello' or 'hi'.";break;

    }

    console.log(result)