+<sect1>Tcl Scripts
+
+<p>
+
+The scripts with the extension <tt/egw/ are HTML files with embedded Tcl.
+Tcl code is initiated with a left curly brace <tt/{/ and is terminated
+with a right curly brace <tt/}/. The Tcl code is executed on the
+top level, i.e. variables are accessed in the global scope.
+Standard Tcl commands, IrTcl commands to access the Z39.50
+communication layer, and
+an extra set of "gateway" commands are available in the embedded Tcl code.
+The extra set of commands are used to communicate with the Europagate
+software. These are:
+
+<descrip>
+<tag/html/ Concatenates the arguments and transfers them to the HTTP server.
+The data may be cached. They are not written until the <tt/egw_flush/ is
+invoked.
+<tag/egw_form/ Inspects CGI form variables.
+<tag/egw_parms/ Inspects URL variables.
+<tag/egw_flush/ Flushes all HTML output.
+<tag/egw_log/ Logs messages.
+<tag/egw_enc/ Encodes URL data.
+<tag/egw_wait/ Waits for events. One of the following events
+will terminate this command: data from a Z39.50 server,
+data from the CGI module, or timeout.
+</descrip>
+
+Note, that except from the <tt/html/ command all commands have a
+<tt/egw_/ - prefix.
+Apart from the new commands, the following global variables are set:
+<descrip>
+<tag/sessionId/ ID of the current user session (integer).
+<tag/env/ Array of environment variables - this is standard Tcl, really.
+</descrip>
+