Control variable - %cv

In this section:

• Caption - %ca[title]
• Window handle - %hw
• Control handle - %lc
• Leave window open - %lw[option]
• Start-up call-back - %sc
• Child window - %ch
• Control variable - %cv
• Create MDI frame - %fr
• Attach window - %aw
• Drag and drop - %dr
• Set window position - %sp
• Set window size - %sz
• Window style - %ww[options]
• Background colour - %bg[colour]
• ClearWin window - %N.Mcw[options]
• Property sheet - %Nps
• Property sheet child - %sh
• Closure control format - %cc
• Delayed auto recall - %dl
• Wallpaper - %wp[bitmap]
• User window - %uw[class_name]
• Screen saver - %sv
• Disable screen saver - %ns
• Taskbar icon - %ti

%cv (Control Variable) is used to establish a control variable for a window that does not use %lw (Leave Window Open). It takes an INTEGER control variable as an argument. This is used to enable another window to attach itself as a child using the %aw (Attach MDI Child Window) format.