1. A method comprising: obtaining job control language (JCL) function choices and parameters associated with the JCL function choices; transmitting the JCL function choices to a graphical user interface; receiving a function choice selection in response to a user interacting with the graphical user interface to specify a job; customizing a panel for display based on the received function choice selection and the parameters associated with the received function choice selection; transmitting the customized panel to the graphical user interface; receiving values for at least a subset of the parameters associated with the received function choice selection via the graphical user interface; mapping the received function choice selection and received values to an associated JCL command; and creating a JCL card that instructs a mainframe computer to execute the specified job based on the mapping.