Please correct my script..
#include <ButtonConstants.au3>
#include <EditConstants.au3>
#include <GUIConstantsEx.au3>
#include <StaticConstants.au3>
#include <WindowsConstants.au3>
#Region ### START Koda GUI section ### Form=G:\Form1.kxf
$Form1 = GUICreate("Kalkulasi", 219, 186, 378, 178)
GUISetBkColor(0x00FFFF)
$Input1 = GUICtrlCreateInput("0", 90, 37, 122, 21)
$Input2 = GUICtrlCreateInput("0", 89, 66, 122, 21)
$Input3 = GUICtrlCreateInput("0", 89, 95, 122, 21)
$Label1 = GUICtrlCreateLabel("Diameter", 8, 39, 60, 23)
GUICtrlSetFont(-1, 10, 800, 0, "Comic Sans MS")
$Label2 = GUICtrlCreateLabel("Thickness", 8, 67, 65, 23)
GUICtrlSetFont(-1, 10, 800, 0, "Comic Sans MS")
$Label3 = GUICtrlCreateLabel("Length", 8, 95, 46, 23)
GUICtrlSetFont(-1, 10, 800, 0, "Comic Sans MS")
$Input4 = GUICtrlCreateInput("", 8, 150, 204, 21)
GUICtrlSetBkColor(-1, 0xE3E3E3)
$Label4 = GUICtrlCreateLabel("", 98, 140, 4, 4)
GUICtrlSetFont(-1, 10, 800, 0, "Comic Sans MS")
$Radio1 = GUICtrlCreateRadio(" x..", 8, 8, 49, 17)
$Radio2 = GUICtrlCreateRadio(" +..", 64, 8, 73, 17)
GUICtrlSetState($radio1, $GUI_CHECKED)
$Label5 = GUICtrlCreateLabel("Volume mm", 8, 130, 64, 20)
GUICtrlSetFont(-1, 8, 800, 2, "Comic Sans MS")
GUISetState(@SW_SHOW)
#EndRegion ### END Koda GUI section ###
While 1
$Msg = GUIGetMsg()
Select
Case BitAND(GUICtrlRead($radio1), $GUI_CHECKED) = $GUI_CHECKED
$x = GUICtrlRead ($Input1)
$y = GUICtrlRead ($Input2)
$z = GUICtrlRead ($Input3)
$c = $x * $y * $z
If StringRegExp(StringLeft([$x-$y], 2)) Then ;<==== How to set $x-$y Only number not for word then show message in input 4
GUICtrlSetData($Input4, $c)
Else
GUICtrlSetData($Input4," Only Number Not Word") ; <======
EndIf
Case BitAND(GUICtrlRead($radio2), $GUI_CHECKED) = $GUI_CHECKED
$x = GUICtrlRead ($Input1)
$y = GUICtrlRead ($Input2)
$z = GUICtrlRead ($Input3)
$cz = $x + $y + $z
GUICtrlSetData($Input4, $cz)
EndSelect
Switch $Msg
Case $GUI_EVENT_CLOSE
Exit
EndSwitch
WEnd