A computer-implemented method includes identifying, in web code to be served to a client, presence of code for generating a form; generating additional, executable code to be run on the client device, the additional, executable code being arranged to identify user input on the client device and modify the form so that data from the user input is received into one or more alternative fields of the form other than a first field to which a user performing the input directed the input; receiving a request from the client device based on completion of input into the form; and converting data from the received request so that data for the one or more alternative fields of the form is directed to the first field of the form for processing by a web server system that initially generated the web code.