How do i stop a timer

Hi

I have a timer that runs to send a mail based on criteria. Problem is....the timer does not stop.....ever.....mailbox flooded, please help urgently.

Private Sub Workbook_Open()
Application.OnTime Now + TimeValue("00:02:00"), "Check1"
End Sub

the code above is what I used....I need something in before close to stop the timer 'cause it does not stop when I close the workbook.

the end result I'm looking for is for the timer to run every 2 minutes and check for the criteria as per the below but, I am not 100% sure the below code is right?

Sub Check1()
Dim c As Range
ActiveSheet.Calculate
For Each c In Range("AI2:AI300")
    If c.Value = "3" Then
        Call Mail43
    End If
Call Timer1
Next c
End Sub

Sub Timer1
Application.OnTime Now + TimeValue("00:02:00"), "Check1"

thank you for the reply, but I need the code to stop the timer running.....when I close the workbook......the timer just keeps on running, so I need to put something in the "before workbook close" event to stop the code from running when I close the workbook.

tried another approach much like you are suggesting.

thank you very much for the assistance bulina2kn

Did you try this?

PHP Code: 

Private Sub Workbook_BeforeClose(Cancel As Boolean)
    Application.OnTime Now + TimeValue("00:02:00"), "Check1", , False
End Sub