WOPEN()
 Opens a new window
------------------------------------------------------------------------------
 Syntax

     WOPEN(<nTopRow>, <nLeftColumn>, <nBottomRow>,
        <nRightColumn>, [<lDelete>]) --> nWindow

 Arguments

     <nTopRow>  Designates the top row.  The value can be between 0 and
     24.

     <nLeftColumn>  Designates the leftmost column.  The value can be
     between 0 and 79.

     <nBottomRow>  Designates the bottom row.  The value can be between 0
     and 24.

     <nRightColumn>  Designates the rightmost column.  The value can be
     between 0 and 79.

     <lDelete>  Designates whether the area of the screen selected for
     the newly opened window is erased (.T.) or not (.F.).  The default value
     (.F.) does not erase the area.

 Returns

     WOPEN() returns a handle to the new window.  If there is an error,
     WOPEN() returns -1.

 Description

     WOPEN() opens a new window.  If a window can be opened, then the
     function returns a number (handle) for this window.  If a window is
     opened with invalid coordinates, WOPEN() returns -1 and the window that
     was active at the time of the function call is still active.

 Notes

     .  Beginning with CA-Clipper 5.01, windows that lie completely
        under the actual screen border, or under the borders defined by
        WBOARD(), can also be opened.

     .  After you open a window, all screen output is redirected to
        the window if it is not written directly into screen memory.  This
        applies to output from CA-Clipper, DOS, and other programs.  If the
        output rows are longer than the window is wide, then there is a line
        feed (i.e. for SCOREBOARD output).

     .  If a shadow has been selected using WSETSHADOW(), the window
        screen area is cleared when you open the window.

 Example

     This function opens a window with the top left corner in row 5 at column
     10, and the bottom right corner in row 20 at column 70.  If the window
     opens successfully, the returned value is 1:

     nWindow := WOPEN(5, 10, 20, 70)