This function is implemented in basic and the source of the function can be found in the file cgi.bas. This function accepts two arguments. The first argument is the code of the state of the http answer that the application is sending. This is usually 200 for normal answers. The second argument is the mime type of the answer. This is text/html for HTML pages.
The state of the http answer should be defined differently using Microsoft IIS. This function automatically takes care of this.