Yes or No Options

[Alex via Digitalmars-d-learn]

Thank you! That helped me a lot.

I'm sure that - in order to get to the point to repeat the whole 
first part of the program - I'll have to read further in the 
instructions I have BUT let's just say that I don't want it to 
repeat the first part of the program but just writeln something 
like "Ok let's do it again!" if I enter Y and press enter.

I now got to the point where the program doesn't quit but if I 
enter "Y" and hit Enter, nothing happens.

I do understand how to define an int and then compare it to a 
number I entered and do something if the number was 
smaller/bigger/the same etc.

But how do I get the programm to simply write a line if I enter a 
letter like Y?

With the code I got here it does not work. What is wrong with 
this part here:

	writeln("Do you want to play again? Y/N?");
	readf(" %s", &yesno);
	readln();
	if (yesno == "Y") {
		writeln("Yeah!");
	}


Doesn't the code mean: Write "Do you want to play again? Y/N?". 
Read keyboard input and define "yesno" by what was entered. And 
then: If what was entered was a "Y", write the following line 
"Yeah!".

Where is my error in thinking?

Sorry guys, I know it's probably something very easy..