Why don't the code challenges allow for proper error detection?

Ok, I've tried finishing this Java Objects course a number of times. The code challenges only give a "Bummer! There is a compiler problem"

Then it says to check the Preview for errors. That doesn't display anything but a blank screen most of the time!

I'm finding these code challenges to be vague at best in terms of what the compiler already sees and what I'm suppose to be coding.

I don't have time to monkey around with forums trying to resolve all issues.

There's a definite need for clarity here. I'm also finding that a lot of concepts are being glossed over, which is leaving some pretty big gaps.

Maybe it's just me... but some of these courses seem awfully ambiguous. Especially in light of the fact that coding syntax is so precise.

Kevin

public class ConferenceRegistrationAssistant {



    public boolean getLineFor(char lastName) {
    int line = 0;
    String mAnswer = "";
      if mAnswer.indexOf(lastName) < "M" {
    line = 1;
    }else{
      line = 2;
    }   





    return line;
  }

}