Write Java Program That Asks User For List Of Names?

I am trying to write a java program that asks the user for a list of names (one per line) until the user enters a blank line. At that point the program should print out the list of names entered, where each name is listed only once (i.e., uniquely) no matter how many times the user entered the name in the program. I am supposed to use an ArrayList for this problem.

My idea for a solution is to create an ArrayList<String>, read each name, i.e., line, entered and then to see if that name is already in the ArrayList. I created a for loop to check each element in the ArrayList but when I try to assign an element to a string variable I get the error "Type mismatch: cannot convert from Object to String". Not sure why that is happening because the ArrayList is defined as a String list.

Here is the code so far.

/*
* File: UniqueNames.java
*/
import acm.program.*;
import java.util.*;

[Code].....