diff --git a/scripts/http-open-proxy.nse b/scripts/http-open-proxy.nse
index 41566f366..3e37c4349 100644
--- a/scripts/http-open-proxy.nse
+++ b/scripts/http-open-proxy.nse
@@ -11,6 +11,8 @@ web page from www.google.com.
 ]]
 
 ---
+-- @args openproxy.url Url that will be requested to the proxy
+-- @args openproxy.pattern Pattern that will be searched inside the request results
 -- @output
 -- Interesting ports on scanme.nmap.org (64.13.134.52):
 -- PORT     STATE SERVICE
@@ -27,8 +29,14 @@ web page from www.google.com.
 --     case-sensitively against "^Server: GWS/".
 -- 2009-05-14 Joao Correa <joao@livewire.com.br>
 --   * Included tests for HEAD and CONNECT methods
---   * Included url arguments
---   * Script now checks for http response status code
+--   * Included url and pattern arguments
+--   * Script now checks for http response status code, when url is used
+--   * If google is used, script checks for Server: gws
+-- 
+-- @usage
+-- nmap --script http-open-proxy.nse \
+--      --script-args 'openproxy={url=<url>,pattern=<pattern>}'
+
 
 author = "Arturo 'Buanzo' Busleiman <buanzo@buanzo.com.ar>"
 license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
@@ -42,7 +50,7 @@ require "url"
 --- If any of the HTTP status below is found, the proxy is potentially open
 --@param result connection result
 --@return true if any of the status is found, otherwise false
-function check(result)
+function check_code(result)
 	local status = false
 	if string.match(result:lower(),"^http.*200.*") then return true end
 	if string.match(result:lower(),"^http.*301.*") then return true end	
@@ -50,6 +58,35 @@ function check(result)
 	return false
 end
 
+--- check pattern, searches a pattern inside a response with multiple lines
+--@param result Connection result
+--@param pattern The pattern to be searched
+--@return true if pattern is found, otherwise false
+function check_pattern(result, pattern)
+	lines = stdnse.strsplit("\n", result)
+	i = 1
+	n = table.getn(lines)
+	while true do
+		if i > n then return false end
+		if string.match(lines[i]:lower(),pattern) then return true end
+		i = i + 1
+	end
+end
+
+--- check, decides what kind of check should be done on the response,
+--- depending if a specific pattern is being used
+--@param result Connection result
+--@param pattern The pattern that should be checked (must be false, in case of
+--code check)
+--@return true, if the performed check returns true, otherwise false
+function check(result, pattern)
+	if pattern 
+		then return check_pattern(result, pattern)
+		else return check_code(result)
+	end
+end
+
+
 portrule = shortport.port_or_service({8123,3128,8000,8080},{'polipo','squid-http','http-proxy'})
 
 action = function(host, port)
@@ -63,12 +100,14 @@ action = function(host, port)
 	-- Default host = nmap.org
 	local test_url = "http://www.google.com"
 	local hostname = "www.google.com"
+	local pattern = "^server: gws"
 
 	-- If arg url exists, use it as url
 	-- If arg hurl exists, use it as host_url
 	-- If arg url exists, but arg hurl doesn't, use url as host_url
 	if(nmap.registry.args.openproxy and nmap.registry.args.openproxy.url) then
 		test_url = nmap.registry.args.openproxy.url
+		pattern = false
 		if not string.match(test_url, "^http://.*") then 
 			test_url = "http://" .. test_url
 			stdnse.print_debug("URL missing scheme. URL concatenated to http://")
@@ -76,14 +115,15 @@ action = function(host, port)
 		url_table = url.parse(test_url)
 		hostname = url_table.host
 	end
- 
+	if(nmap.registry.args.openproxy and nmap.registry.args.openproxy.pattern) then pattern = ".*" .. nmap.registry.args.openproxy.pattern .. ".*" end
+ 	
 	-- Trying GET method!
 	req = "GET " .. test_url .. " HTTP/1.0\r\nHost: " .. hostname .. "\r\n\r\n"
 	stdnse.print_debug("GET Request: " .. req)
 	local status, result = comm.exchange(host, port, req, {lines=1,proto=port.protocol, timeout=10000})
 
 	if status then	
-		lstatus = check(result)
+		lstatus = check(result, pattern)
 		if lstatus then	
 			supported_methods = supported_methods .. "GET "
 			fstatus = true
@@ -96,7 +136,7 @@ action = function(host, port)
 	local status, result = comm.exchange(host, port, req, {lines=1,proto=port.protocol, timeout=10000})
 
 	if status then
-		lstatus = check(result)
+		lstatus = check(result, pattern)
 		if lstatus then	
 			supported_methods = supported_methods .. "HEAD "
 			fstatus = true
@@ -110,7 +150,7 @@ action = function(host, port)
 	local status, result = comm.exchange(host, port, req, {lines=1,proto=port.protocol, timeout=10000})
 
 	if status then
-		lstatus = check(result);
+		lstatus = check(result, false);
 		if lstatus then	
 			supported_methods = supported_methods .. "CONNECT"
 			fstatus = true