How do you upload a file to a document library in sharepoint?

string filePath = @"C:\styles\MyStyles.css"; 
string siteURL = "http://example.org/"; 
string libraryName = "Style Library"; 

using (SPSite oSite = new SPSite(siteURL)) 
{ 
    using (SPWeb oWeb = oSite.OpenWeb()) 
    { 
        if (!System.IO.File.Exists(filePath)) 
            throw new FileNotFoundException("File not found.", filePath);                     

        SPFolder libFolder = oWeb.Folders[libraryName]; 

        // Prepare to upload 
        string fileName = System.IO.Path.GetFileName(filePath); 
        FileStream fileStream = File.OpenRead(filePath); 

        //Check the existing File out if the Library Requires CheckOut
        if (libFolder.RequiresCheckout)
        {
            try {
                SPFile fileOld = libFolder.Files[fileName];
                fileOld.CheckOut();
            } catch {}
        }

        // Upload document 
        SPFile spfile = libFolder.Files.Add(fileName, fileStream, true); 

        // Commit  
        myLibrary.Update(); 

        //Check the File in and Publish a Major Version
        if (libFolder.RequiresCheckout)
        {
                spFile.CheckIn("Upload Comment", SPCheckinType.MajorCheckIn);
                spFile.Publish("Publish Comment");
        }
    } 
}