http://code.google.com/p/syntaxhighlighter/
You can change the starting line number by adding firstline[#].
<textarea name="code" class="c#:firstline[42]" rows="15" cols="100">
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string path = "";
string safeReferrer = null;
FileInfo fileInfo = new FileInfo(string.Format("{0}/{1}", path, image));
int index = 0;