ASP.NET 汉字转化为GB2312时出问题了

在网站上搜索时“兰芝睡眠面膜20ML”在转换为GB2312时结果为：/x5170/x829D/x7761/x7720/x9762/x819C20ML 在将他转换为：汉字时报错：字符串的末尾有其他无法分析的字符应该是20ml这个没转换对，我用“兰芝睡眠面膜”这个查询就没问题，大家帮帮忙啊。
我两个函数为：
汉字转换为GB2312：
Public Function Escape(ByVal src As String) As String
        If src Is Nothing Then
            Return Nothing
        End If

        Dim i As Integer
        Dim j As Char
        Dim tmp As StringBuilder = New StringBuilder

        For i = 0 To src.Length - 1
            j = src.Chars(i)
            If Char.IsDigit(j) Or Char.IsLower(j) Or Char.IsUpper(j) Then
                tmp.Append(j)
            ElseIf (AscW(j) < 16 * 16) Then
                tmp.Append("%")
                If AscW(j) < 16 Then
                    tmp.Append("0")
                End If
                tmp.Append(Hex(AscW(j)))
            Else
                tmp.Append("%u")
                If (AscW(j) < 16 * 16 * 16) Then
                    tmp.Append("0")
                End If
                tmp.Append(Hex(AscW(j)))
            End If
        Next
        Return tmp.ToString()
    End Function

GB2312转换为汉字：
Public Function EscToStr(ByVal c As String) As String
        Dim tmp, str1, str2, str3, str4 As String
        Dim i, outend1, outend2 As Integer
        i = 1
        outend1 = 1
        Do While outend1 <> 0
            str1 = c
            outend1 = InStr(i, str1, "/x")
            i = outend1 + 1
            outend2 = InStr(i, str1, "/x")

            If outend2 = 0 Then
                outend2 = Len(str1) + 1
            End If
            str2 = Mid(str1, outend1 + 2, outend2 - outend1 - 2)
            str3 = "&H" & str2
            str4 = ChrW(str3)
            tmp = tmp & str4
            If outend2 = (Len(str1) + 1) Then
                outend1 = 0
            End If

        Loop

        EscToStr = tmp
    End Function

--------------------编程问答-------------------- 自己顶下 --------------------编程问答-------------------- 直接
String a = Microsoft.JScript.GlobalObject.escape("兰芝睡眠面膜20ML");

即可

注意添加jscript.dll引用 --------------------编程问答-------------------- 我用VB.NET哦，好像没有这个吧String a = Microsoft.JScript.GlobalObject.escape("兰芝睡眠面膜20ML");
不懂 --------------------编程问答--------------------

补充：.NET技术 ,  ASP.NET