how to add emoticons in our chat application

public class EmoticonRender()
{
 
  private List<keyvaluepair<string,string>> _dictionary = new List<keyvaluepair<string,string>>() 
  {
    new KeyValuePair<string,>(":-)", "smile.png"),
    new KeyValuePair<string,>(";-(", "cry.png")
  }
 
  public string Parse(string text)
  {
    foreach(KeyValuePair<string,> kvp in _dictionary)
    {
      text = text.Replace(kvp.Key, "<img src="\""" kvp.value="" />");
    }
    return text;
  }
 
}

string text = "hello :-) don't be sad ;-(";
EmoticonRender parser = new EmoticonRender();
string parsedText = parser.Parse(text);