What’s wrong with this program?

Question

This program is producing correct output for "Belt" and "Tie" input. But for the other inputs ("Scarf" and "Cufflinks") program output is "No match found". Anyone can fix the error.

// Debug06-01
// Lists items for sale and their prices
using System;
public class DebugSix01
{
public static void Main()
{
string[] items = { "Belt", "Tie", "Scarf", "Cufflinks"};
double[] prices = { 29.00, 35.95, 18.50, 112.99 };

Console.Write("Items for sale: ");

string enterItem = Console.ReadLine();

int arrayPosition = Array.BinarySearch(items, enterItem);

if (arrayPosition < 0)
Console.WriteLine("No match found");
else
Console.WriteLine("Price {0}", prices[arrayPosition].ToString("c"));

Console.ReadKey();
}
}