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public void setAuthor(String authorName)
{
authorName = authorName;
}

here compiler gets ambiguity because of parameter of function and class variable having same name.
public...

In "While loop" your not comparing value your assigning value to 'more' and your end while loop there only.It is suggestion for u must know about 'scope of variable' and 'while loop' and understand...

U had declared variables but didn't assigned the values yet.
It is suggestion that u must know about "local variable and class variable " and u must know about "this" keyword in java it help in...

/**Code removed by moderator*/
it will work properly