private void GenerateThumb(string sourcepath, string folder, string prefix, int width, 
    bool overwrite, bool deletecurrupt)
{
    double factor;
    System.Drawing.Image thumbnail, fullimage;        

    string file = Path.GetFileName(sourcepath);
    string filethumb = folder + (folder.EndsWith(@"\")? "" : @"\") 
            + prefix + "." + file;
    if(overwrite || (!overwrite && !File.Exists(filethumb)))
    {
        try
        {
            fullimage = System.Drawing.Image.FromFile(sourcepath);

            factor = fullimage.Width/(double)width;
            thumbnail = fullimage.GetThumbnailImage(width, 
                (int)(fullimage.Height/factor), null, IntPtr.Zero);
            thumbnail.Save(filethumb, System.Drawing.Imaging.ImageFormat.Jpeg);
        }
        catch(OutOfMemoryException)
        {
            if(deletecurrupt)
                File.Delete(sourcepath);
        }
    }
}