title: Dictionary ContainsKey() Doesn't compare string values
body: <p>I'm a noobie to C# and don't understand why <code>ContainsKey()</code> won't return true with the values <code>bid_amount</code> and <code>bid_amount</code>. </p>
  
  <p>I have a long string <code>("key=value, key=value...")</code> that is split on <code>,</code> and then <code>=</code> created into a dictionary. But when I test for a known key in the dict <code>bid_amount</code> it always returns false.</p>
  
  <p>Is there a way to compare values using ContainsKey()?
  What exactly am I missing?</p>
  
  <pre><code>string[] responseStringSplit = responseString.Split (new []{ ',' });
  Dictionary&lt;string,string&gt; responseDict = new Dictionary&lt;string, string&gt; ();
  
  foreach (string word in responseStringSplit) 
  {
      string[] splitString = word.Split (new[]{ ':' });
      if (splitString.Length &gt; 1) 
      {
         responseDict.Add(splitString [0],splitString [1]);
      } 
      else 
      {
         Debug.Log ("CouldNotSplit:" + word);
      }
  }
  
  foreach (KeyValuePair&lt;string, string&gt; entry in responseDict)
  {
      Debug.Log (entry.Key + "=" + entry.Value);
      if (responseDict.ContainsKey ("bid_amount")) 
      {
        Debug.Log ("found bid amount");
      }
  }
  </code></pre>