C#

private void outputnoscript(StreamReader reader, StreamWriter writer)
		{
			string line = "";
			int opencounter = 0;
			int closecounter = 0;

			while(line!=null)
			{
				line = reader.ReadLine();

				if (line!=null)
				{
					MatchCollection opencollection = Regex.Matches(line, "<script",RegexOptions.IgnoreCase);
					
					for (int i = 0; i < opencollection.Count; i++)
					{
						//insert a <!--- at the position in the current match, +5 for every <!--- already inserted
						Match openmatch = opencollection[i];
						line.Insert(openmatch.Index + opencounter, "<!---");
						opencounter += 5;
					}

					MatchCollection closecollection = Regex.Matches(line, "/script>", RegexOptions.IgnoreCase);
				
					for (int i = 0; i < closecollection.Count; i++)
					{
						//insert a ---> at the position in the current match, +4 for every ---> already inserted
						Match closematch = closecollection[i];
						//plus 8 is to accomodate for the fact that regex returns the position of "/" in "/script>"
						line.Insert(closematch.Index + 8 + closecounter, "--->");
						closecounter += 4;
					}
					
					writer.WriteLine(line);
				}
			}
		}