4. A computer system comprising: at least one computer configured to, generate a web service providing a programming interface between a web application and a user application by: creating a script of a navigation flow of at least one transaction of the web application, the navigation flow representative of an interaction between a user and a web application interface of the web application during the at least one transaction in the script of the navigation flow; creating a text file describing a function and at least one of an input parameter or an output parameter, the function to be called by the user application for executing the at least one transaction; creating web service interface code corresponding to the call of the function as described in the text file; and creating web service implementation code for executing the interaction based on the script of the navigation flow, wherein the web service implementation code uses the web service interface code to implement the function without the user; wherein creating web service implementation code including generating the navigation flow using a regression test tool; wherein the script of the navigation flow is written in a script language.
4. A computer system comprising: at least one computer configured to, generate a web service providing a programming interface between a web application and a user application by: creating a script of a navigation flow of at least one transaction of the web application, the navigation flow representative of an interaction between a user and a web application interface of the web application during the at least one transaction in the script of the navigation flow; creating a text file describing a function and at least one of an input parameter or an output parameter, the function to be called by the user application for executing the at least one transaction; creating web service interface code corresponding to the call of the function as described in the text file; and creating web service implementation code for executing the interaction based on the script of the navigation flow, wherein the web service implementation code uses the web service interface code to implement the function without the user; wherein creating web service implementation code including generating the navigation flow using a regression test tool; wherein the script of the navigation flow is written in a script language. 7. The system of claim 4 , wherein the web service is implemented in a web server hosting the web application.