hitTest(<nRow>, <nColumn>) --> <nHitTest>

        Determines if the screen position specified by <nRow> and <nColumn>
        is on the TBrowse object.

        Applicable Hit Test Return Values
        ---------------------------------------------------------------------
        Value  Constant       Description
        ---------------------------------------------------------------------
        0      HTNOWHERE      The screen position is not within the region of
                              the screen that the TBrowse occupies
        -1     HTTOPLEFT      The screen position is on the TBrowse border's
                              top-left corner
        -2     HTTOP          The screen position is on the TBrowse's top
                              border
        -3     HTTOPRIGHT     The screen position is on the TBrowse border's
                              top-right corner
        -4     HTRIGHT        The screen position is on the TBrowse's right
                              border
        -5     HTBOTTOMRIGHT  The screen position is on the TBrowse border's
                              bottom-right corner
        -6     HTBOTTOM       The screen position is on the TBrowse's bottom
                              border
        -7     HTBOTTOMLEFT   The screen position is on the TBrowse border's
                              bottom-left corner
        -8     HTLEFT         The screen position is on the TBrowse's left
                              border
        -5121  HTCELL         The screen position is on a cell
        -5122  HTHEADING      The screen position is on a heading
        -5123  HTFOOTING      The screen position is on a footing
        -5124  HTHEADSEP      The screen position is on the heading separator
                              line
        -5125  HTFOOTSEP      The screen position is on the footing separator
                              line
        -5126  HTCOLSEP       The screen position is on a column separator
                              line
        ---------------------------------------------------------------------

        Button.ch contains manifest constants for the TBrowse:hitTest()
        return values.