ICON
Dialog's icon. This icon will be used when the dialog is minimized.
Value
Name of a IUP image.
Default: NULL
Notes
Icon sizes are usually less than or equal to 32x32.
The Windows SDK recomends that cursors and icons should be implemented as resources rather than created at run time.
On Motif, it only works with some window managers, like mwm and gnome. Icon colors can have the BGCOLOR values, but it works better if it is at index 0.