function chkEmail(email)
      on error resume next
      dim i,l,pos1,pos2
      chkEmail=true
      if isnull(email) then chkEmail=false:exit function
      pos1= instr(email,"@")
      pos2=instrRev(email,".")
      if not(pos1>0) or not (pos2>0) or pos1>pos2 then             
         chkEmail=false
      end if
      if err.number<>0 then err.clear
  end function