AutoHotkey GetWinTitle when current window changes

Question

I'm trying to make an ahk script that alerts you when a new window is opened (or brought back to focus). In other words, I want it to detect when the current window changes. I've tried comparing the window names to detect a difference:

    0::
    WinGetTitle, title, A
    windowTitle=%title%
    MsgBox, "The current window is %title%."
    return

    9::
    WinGetTitle, title2, A
    if (%title2% = %title%)
    {
        success=1
    }
    else
    {
        MsgBox, "The current window changed to %title2%."
    }
    return

But,
1)I'm apparently using illegal characters in the variables; and
2)I'd rather use a different method than this;

Thanks in advance!

PS I would like the alert to contain the name of the current window.

Answer 1

CurrentTitle := ""

SetTimer, CheckWindow, 1000
return

CheckWindow:
    WinGetTitle, NewTitle, A
    if (CurrentTitle != NewTitle){
        ToolTip % "Window changed to: " NewTitle
        CurrentTitle := NewTitle
    }
    return