Methods and apparatus, including computer program products, for capturing data of a predefined type from a user. The techniques include sending a markup language page to a browser on a client; interpreting the markup language page by the browser to receive data from the user in a transfer format; transferring the data in the transfer format to an object on a server; storing the data by the object in the transfer format; converting the data from the transfer format to a process format by the object; checking the compliance of the data with a predefined rule by the object; and if the data complies with the predefined rule, forwarding the data in the process format by the object to the application; else, resending the markup language page to the browser with the data in the transfer format.