The parameters srow, scol, erow, ecol (any numeric type) mark the upper left and lower right corners of the text editing box. Note that the size of the box does not affect the amount of text that can be edited, although it may affect the way the text is wrapped. See the flags TXF_HSCROLL, TXF_VSCROLL, TXF_FITVIEW.

If the TXF_POPOP bit is set in the flags parameter, the pop-up dialog will initially occupy the space specified by these row/column coordinates, but the user will be able to drag and resize the dialog. If the coordinates are negative, they are interpreted as pixel coordinates, allowing you to position the popup window relative to the desktop rather than the dialog or main A-Shell window.