#include <math.au3>
$I_Var = InputBox('Odd or Even', 'Enter a number:')
$I_Result = _MathCheckDiv($I_Var, 2)
If $I_Result = -1 Or @error = 1 Then
   MsgBox(0,'','You did not enter a valid number')
ElseIf $I_Result = 1 Then
   MsgBox(0,'','Number is odd')
ElseIf $I_Result = 2 Then
   MsgBox(0,'','Number is even')
Else
   MsgBox(0,'','Could not parse $I_Result')
EndIf