You can define a pull-down choice as being preselected with the CHECKVAR and MATCH attributes of the PDC tag. The CHECKVAR attribute specifies the name of a variable that you set at run time to indicate if the pull-down choice should be preselected. The MATCH attribute defines a value that causes the choice to be preselected. ISPF compares the value of the variable named for the CHECKVAR attribute to the MATCH value, and if they are equal, the choice appears preselected when the pull-down is displayed.

Continuing with the library application, assume that the user can view the files in the library sorted by name, owner, date, or size. Preselecting a pull-down choice provides a visual cue to the user of the current sort order.

To preselect any of the pull-down choices, the same CHECKVAR value is specified for each choice, and a unique MATCH value is specified for each choice. The application variable specified with CHECKVAR is set to the MATCH value to indicate the sorting option being used. The variable specified with CHECKVAR is changed each time the sorting option is changed. This provides a visual reminder to the user of how the files are sorted.