Joined: 14 Mar 2007 Posts: 8657 Location: Back in jolly old England
Sigh .......... I can only assume that it is easier to post here than it is to read the manual yourself
ISPF uses dialog variables to communicate data between the dialog management services and the dialog elements. A dialog variable's value is a character string that can vary in length from 0 to 32K bytes. Some services restrict the length of dialog variable data.
Dialog variables are referred to symbolically. The name is composed of 1-8 characters (6 for FORTRAN). Alphanumeric characters A-Z, 0-9, #, $, or @ can be used in the name, but the first character cannot be numeric. APL variable names cannot contain #, $, or @.
Dialog variables can be used with panels, messages, and skeleton definitions, as well as within dialog functions. For example, a dialog variable name can be defined in a panel definition, and then referred to in a function of the same dialog. Or, the variable can be defined in a function, then used in a panel definition to initialize information on a display panel, then later used to store data entered by the user on the display panel.
For functions coded in a programming language other than APL2, the internal program variables that are to be used as dialog variables can be identified to ISPF and accessed using the ISPF variable services. The use of STEM or COMPOUND variables within a REXX procedure is not supported by ISPF. For a function coded as CLIST or REXX command procedures or as an APL2 procedure, variables used in the procedure are automatically treated as dialog variables. In this case, no special action is required to define them to ISPF.