LPARAMETERS button, shift, x, y
cStruct=n2dw(x)+n2dw(y)+n2dw( 0 )+n2dw( 0 )+n2dw( 0 )
r=SendMessage(this.hWnd, 4114 , 0 ,cStruct)  &&  ItemIndex
thisform.Caption=iif(r='-1','',STR(r+ 1 ))

FUNCTION n2dw (lnValue) 
#DEFINE m0        256  
#DEFINE m1      65536  
#DEFINE m2   16777216  
    LOCAL b0, b1, b2, b3 
    b3 = Int(lnValue/m2) 
    b2 = Int((lnValue - b3*m2)/m1) 
    b1 = Int((lnValue - b3*m2 - b2*m1)/m0) 
    b0 = Mod(lnValue, m0) 
RETURN Chr(b0)+Chr(b1)+Chr(b2)+Chr(b3)

DECLARE INTEGER SendMessage IN user32; 
    INTEGER hWnd,; 
    INTEGER Msg,; 
    INTEGER wParam,; 
    string @ lParam