下列Encode函数的功能是对字符串s里的数字字符进行加密,加密方法是增加序数n(数字字符加n后还是在数字字符范围内),如n=3,"Text123789"-->"Text456012"。请在_________处填入适当的内容完善程序。Function Encode(ByVal s$, ByVal n) As String Dim i%, c$, cvalue% For i = 1 To Len(s) c = Mid(s, i, 1) Select Case c Case "0" To "9" cvalue = Val(c) + n If cvalue > 9 Then _________ c = CStr(cvalue) 'CStr()函数将数值转换成数字字符 End Select Encode = Encode & c NextEnd Function