Arduino Webserver Post problem

Hello,
I have found a nice web-server-interface from Alessandro calzavara:
http://www.arduino.cc/playground/Code/WebServer
The script is to big to post this here.
No I try to use the feedbackinformation of the "prova" textbox.
Anythink what I try does not work.
When I understand i true the field name and the contant will saved in the char vars.
I have chanced this to wstring
String vars=String(STRING_VARS_SIZE)
With this I think I can use the: contains option.

I tryed to include in the "Send Pages" section:

if (vars.contains("prova=X"){
client.print(vars);
}

But the POST information will print everytime... >:(
I hope that someone can help me....

Regards
Rafael

Ok I have found that I used the wron point to use the vars...
I have to do this in the loop not in the function.

...question closed....