Stop Macro if Condition Met

Hi Friends,

I tried the belwo code to stop Macro if column "A" has the value "#NA" but i am getting error.
{if the Value "#NA" not in the column "A" then macro can continue to run}

Sub Stopmacro()

If ActiveSheet.Range("A2:A" & LastRow).Value = "#NA" Then
   MsgBox ("Please check the alainment")
   Exit Sub
  End If
 End Sub

Kindly help to recitify the error.