Read Simple Text from .txt

Recently I was asked to create a portion on a web application. The basic requirement was to make the app able to read simple text from a text file (.txt) in a configurable location. The path would be located in the web.config and might be both a Web (URL) or physical (windows-style) address. In addition the file may or not exist... so here is the code I wrote:

        private string GetTextFromFile() 
        { 
            string returnValue = string.Empty; 
 
            try 
            { 
                string path = Convert.ToString(ConfigurationManager.AppSettings["keyTextFile"]); 
                StringBuilder sb = new StringBuilder(); 
 
                // make the difference between Url and Windows-style Path 
                if (path.Contains("http") || path.Contains(Path.AltDirectorySeparatorChar)) 
                { 
                    path = path.TrimEnd('/'); 
                    path = sb.Append(path).Append("//").Append("theFile.txt").ToString(); 
 
                    HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(path); 
                    WebResponse response = request.GetResponse(); 
                    Stream stream = response.GetResponseStream(); 
                    StreamReader reader = new StreamReader(stream); 
                    returnValue = reader.ReadToEnd(); 
                } 
                else 
                { 
                    path = Path.Combine(path, "theFile.txt"); 
 
                    if (File.Exists(path)) 
                    { 
                        using (StreamReader sr = new StreamReader(path)) 
                        { 
                            returnValue = sr.ReadToEnd(); 
                        } 
                    } 
                } 
            } 
            catch 
            { 
                returnValue = string.Empty; 
            } 
 
            return returnValue; 
        }