ArrayList to toString()

ArrayList to toString()

Im having trouble printing the ArrayList through to the toString. It says
that I can not convert an ArrayList to an String. Here my code if anyone
can help.
package edu.purse.test;
import java.util.ArrayList;
public class Purse
{
ArrayList<String> coins = new ArrayList<String>();
public Purse()
{
}
public void addCoin(String coinName)
{
coins.add(coinName);
}
public String toString()
{
return coins;
}
}
package edu.purse.test;
public class PurseTester {
public static void main(String[] args) {
Purse p = new Purse();
p.addCoin("Quarter");
p.addCoin("Dime");
System.out.println(p.toString());
}
}