#include <GUIConstantsEx.au3>

Global $was_stop = 0

GUICreate("My GUI Button")
$Button_1 = GUICtrlCreateButton("Button_1", 10, 30, 100)
$Button_2 = GUICtrlCreateButton("Button_2", 120, -1)
GUISetState()

While 1
    $msg = GUIGetMsg()
    Select
        Case $msg = $GUI_EVENT_CLOSE
            ExitLoop
        Case $msg = $Button_1
            _Function1()
    EndSelect
WEnd

Func _Function1()
    $was_stop = 0
    for $i=1 to 100
    While 1
        If IsStop() Then Return
        ConsoleWrite("running" & @CRLF)
        ; some code 1
        ; ...
        ;If IsStop() Then Return
        ; some code 2
        ConsoleWrite("runningaaaa" & @CRLF)
        Sleep(100)
        ExitLoop
     WEnd
      While 1
         If IsStop() Then Return
        ConsoleWrite("runningccccc" & @CRLF)
        ; some code 1
        ; ...
        ;If IsStop() Then Return
        ; some code 2
        ConsoleWrite("runningaaaabbbbb" & @CRLF)
        ConsoleWrite("runningaaaabbbbbcccc" & @CRLF)
        Sleep(100)
        ExitLoop
     WEnd
     Next
EndFunc

Func IsStop()
    If $was_stop Then Return 1
    If GUIGetMsg() = $Button_2 Then
        $was_stop = 1
        Return 1
    EndIf
    Return 0
EndFunc