Couple of things.

Did you store the StartBlink macro in a standard code module, and the
worksheet_change procedure in the worksheet code module?

This is an impossible condition

If Target.Value 300 And Target.Value < 200 Then

It cannot possibly be 300 and <200. You Want


If Target.Value 300 Or Target.Value < 200 Then


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HTH

Bob

"tpeter" wrote in message
...
I have a worksheet (sheet2, range a13:a100) that has a calculation for the
amount of flow. I want the cell to flash if the result is <200 or 300,
if
the cell is blank or not a number I don't want anything to happen. I have
found some similar postings but can't figure out what I am missing. Any
help
would be greatly appreciated:


Public Sub Worksheet_Change(ByVal Target As Range)
Dim BlinkRange As Range

Set BlinkRange = Range("A1:A100")

If Not Intersect(Target, BlinkRange) Is Nothing Then
If Target.Value 300 And Target.Value < 200 Then
StartBlink

If Target.Value = "" Then
StopBlink
End If
End If
End If
End Sub

Public Sub StartBlink()

Dim myBlinkRange As Range
Dim RunWhen As Long

Set BlinkRange = Range("a13:a100")

With myBlinkRange
If .Font.ColorIndex = 3 Then
.Font.ColorIndex = xlColorIndexAutomatic
Else
.Font.ColorIndex = 3
End If
End With

RunWhen = Now + TimeSerial(0, 0, 1)
Application.OnTime RunWhen, "StartBlink", , True

End Sub