add lua page example with the form submitting

examples/lua/prime_numbers.lp

@@ -0,0 +1,42 @@
+<?
+  -- Lua server pages have full control over the output, including HTTP
+  -- headers they send to the client. Send HTTP headers:
+  print('HTTP/1.0 200 OK\r\nContent-Type: text/html\r\n\r\n')
+?>
+
+<html>
+  <p>Prime numbers from 0 to 100, calculated by Lua:</p>
+ <?
+    function is_prime(n)
+      if n <= 0 then return false end
+      if n <= 2 then return true end
+      if (n % 2 == 0) then return false end
+      for i = 3, n / 2, 2 do
+        if (n % i == 0) then return false end
+      end
+      return true
+    end
+
+    for i = 1, 100 do
+      if is_prime(i) then print('<span>' .. i .. '</span>&nbsp;') end
+    end
+
+ ?>
+
+ <p>Reading POST data from Lua (click submit):</p>
+ <form method="POST" ><input type="text" name="t1"/><input type="submit"></form>
+
+ <pre>
+   POST data: [<?  print(read())?>]
+   request method: [<? print(request_info.request_method) ?>]
+   IP/port: [<? print(request_info.remote_ip, ':', request_info.remote_port) ?>]
+   URI: [<? print(request_info.uri) ?>]
+   HTTP version [<? print(request_info.http_version) ?>]
+   HEADERS:
+   <?
+     for name, value in pairs(request_info.http_headers) do
+       print(name, ':', value, '\n')
+     end
+   ?>
+</pre>
+</html>