rem 显示左边的n个字符(自动识别汉字)
Function LeftTrue(str,n)

      If len(str)<=n/2 Then
            LeftTrue=str
      Else
            Dim TStr
            Dim l,t,c
            Dim i
            l=len(str)
            t=l
            TStr=""
            t=0
            for i=1 to l
                  c=asc(mid(str,i,1))
                  If c<0 then c=c+65536
                  If c>255 then
                        t=t+2
                  Else
                        t=t+1
                  End If
                  If t>n Then exit for
                  TStr=TStr&(mid(str,i,1))
            next
            LeftTrue = TStr
      End If

End Function