Data types used by the splitpane control

Three different data structures are defined to interface with the splitpane control:
SPLITCTLDATA
this structure is used in dialog scripts and with WinCreateWindow() to initialize the splitpane to non-default values.
SPLITPANECHILD
this structure is used by the WinCreateSplitPane() API and describes essential data needed for the creation of a child pane.
SPLITPCREATE
this structure is used by the WinCreateSplitPane() API and includes all the data needed to create a splitpane control.