....
Function button_press (c As Ihandle Ptr, a As Integer, b As Integer) As Integer
      ? a, b
      IupSetAttribute(c, "FGCOLOR" & a & ":" & b, "255 0 0")      
      IupUpdate (c)
      Return IUP_DEFAULT
End Function
.....

#Include Once "IUP/iup.bi"
#Include Once "IUP/iupcontrols.bi"
#Include Once "windows.bi"
'#Include Once "inc/iupcd.bi"

Sub _init_ Constructor
     IupOpen(0,0)
     IupControlsOpen()
End Sub

Sub _exit_ Destructor
     IupClose()
End Sub

Function button_press (c As Ihandle Ptr, a As Integer, b As Integer) As Integer
     IupStoreAttribute(c,"FGCOLOR" & a & ":" & b,"255 0 0")
     IupUpdate (c)
     Return IUP_DEFAULT
End Function

Function windowproc(hwnd As HWND,msg As UINT,wParam As WPARAM,lParam As LPARAM) As Integer
     Select Case msg
         Case WM_DESTROY
             PostQuitMessage(0)
     End Select
     Return DefWindowProc(hwnd,msg,wparam,lparam)
End Function

Function create_mat() As Ihandle Ptr
     Dim As Ihandle Ptr mat = IupMatrix(NULL)

     IupSetAttribute(mat, "NUMCOL", "1")
     IupSetAttribute(mat, "NUMLIN", "3")
     IupSetAttribute(mat, "NUMCOL_VISIBLE", "1")
     IupSetAttribute(mat, "NUMLIN_VISIBLE", "3")
     IupSetAttribute(mat, "EXPAND", "NO")
     IupSetAttribute(mat, "SCROLLBAR", "NO")

     IupSetAttribute(mat, "0:0", "Inflation")
     IupSetAttribute(mat, "1:0", "Medicine ")
     IupSetAttribute(mat, "2:0", "Food")
     IupSetAttribute(mat, "3:0", "Energy")
     IupSetAttribute(mat, "0:1", "January 2000")
     IupSetAttribute(mat, "1:1", "5.6")
     IupSetAttribute(mat, "2:1", "2.2")
     IupSetAttribute(mat, "3:1", "7.2")

     IupSetAttribute(mat,"BGCOLOR1:0", "255 128 0")
     IupSetAttribute(mat,"BGCOLOR2:1", "255 128 0")
     IupSetAttribute(mat,"FGCOLOR2:0", "100 0 128")
     IupSetAttribute(mat,"FGCOLOR1:1", "255 0 128")

     IupSetCallback(mat, "CLICK_CB", Cast(Icallback,@button_press))
     Return mat
End Function

Function main Cdecl (frame As IHandle Ptr) As Integer
     Dim As HWND hParent = CPtr(HWND,IupGetAttribute(frame,"WID"))
     Dim As hwnd hwnd = CreateWindowEx(0,"#32770","Главное окно",WS_VISIBLE Or WS_OVERLAPPEDWINDOW,100,100,300,300,0,0,0,0)
     SetWindowLong(hwnd,GWL_WNDPROC,@windowproc)
     SetParent(hParent,hwnd)
     SetWindowLong(hParent,GWL_STYLE,WS_CHILD Or WS_VISIBLE)
     Return IUP_DEFAULT
End Function

Sub func_1 ()
     Dim As Ihandle Ptr _cbox, dlg, hbox

     _cbox = IupCbox(create_mat(), NULL)
     'IupSetAttribute(_cbox,"SIZE","480x200")

     hbox = IupSetAttributes(IupHbox(_cbox, NULL), "MARGIN=10x10")

     dlg = IupDialog(hbox)
     IupSetHandle("dlg",dlg)
     IupSetCallback(dlg,"MAP_CB"  ,@main)

End Sub

func_1()
IupShowXY(IupGetHandle("dlg"),0,0)

IupMainLoop()