title: Deleting a value only from a key on HashMap
body: <p>I have set up a HashMap which populates with customers details as values (name, postcode, item) and the keys being say Customer1, Customer2 etc.</p>
  
  <p>I want a method to delete just value "item" from each key, my code at the moment is as per below but when i run it the "item" value from argument isn't deleted.</p>
  
  <pre><code>public void deleteThisValue(String value)
  {
      if (this.customer.containsValue(value))
      {
          this.customer.remove(value);
      }
  }
  </code></pre>
  
  <p>Now in my head this works but it obviously doesn't, can anyone shed any light on this matter?</p>
  
  <p>Thanks</p>