Creates a combobox control. A combobox control gives the user a selection of items and allows them to enter a selection not listed. A combobox is two controls in one: a listbox control and an edit control.
If you wish to create an edit control (a combobox without a listbox) set the height to a size in which the listbox doesn't fit.
parent input is the name of the window that owns the new combobox.
If no window or dialog with that name exists, then the FMSLogo screen window is used as the parent.
name input identifies the new combobox and must be a unique word.
xpos input is the X coordinate where the upper-left corner of the new combobox is placed.
ypos input is the Y coordinate where the upper-left corner of the new combobox is placed.
width input is the width of the new combobox.
height input is the height of the new combobox.
If the parent of the combobox is the FMSLogo screen window, then the
height inputs are all given in turtle coordinates.
Otherwise, they are given in "dialog units", the origin is the upper-left corner of the parent, and Y values increase as you move down the screen.
Create a combobox in a new window:
WINDOWCREATE "main "mywindow "mytitle 0 0 100 100  COMBOBOXCREATE "mywindow "mycombo 25 25 50 50 ; Delete the window and its combobox. WINDOWDELETE "mywindow
Create a combobox on the FMSLogo screen window:
COMBOBOXCREATE "main "mycombo 25 25 100 100 ; Delete all windows. WINDOWDELETE "main