title: Values not appending to my NSMutableDictionary
body: <p>I'm trying to add some vales to a NSMutableDictionary dynamically. However, using the following code, I'm adding values using the first letter as the key to a temporary dictionary and then finally adding it to my names dictionary but it just overwrites each value for it's corresponding key</p>
  
  <pre><code>NSMutableDictionary *dictionary = [[[NSMutableDictionary alloc] init] autorelease];
  for (NSString *drugStr in listContents) {
      NSString *substring = [drugStr substringToIndex:1];
      [dictionary setValue:drugStr forKey:substring];     
  }
  names = [[NSDictionary alloc] initWithDictionary:dictionary];
  [dictionary release];
  </code></pre>
  
  <p>What am I doing wrong?</p>