string html = "<IMG tyle='gz' style='Z-INDEX: 1; LEFT: 90px; POSITION: absolute; TOP: 90px' src='' border=0/>";html = Regex.Replace(html, @"(<img\s+)tyle='[^']*'\s+(style='[^']*?left:\s*)(?<left>\d+)([^']*?top:\s*)(?<top>\d+)([^']*'[^>]*>)", new MatchEvaluator(Disp), RegexOptions.IgnoreCase);