Conventional web interfaces are statically designed for a client application to interactively collect data from inputs by users in performing a transaction with a web service program.  When multiple client applications share the web service program, each client application has similar but not identical requirements in collecting data to perform the transaction.  Because a conventional web interface collecting data must be implemented corresponding to a respective data collecting rule, the web service program needs a same number of web interfaces as the number of data collecting rule, regardless of similarities among data collecting rules.  Also, when a data collecting rule is changed, a corresponding web interface also should be modified to reflect such changes made in the data collecting rule. 
Thus, there is a need for a system and associated method that overcomes at least one of the preceding disadvantages of current methods and systems for building a web interface of a service program shared among multiple client applications.