MD5 in VB.NET/C# & ASP.NET (.NET Framework 1.1,2.0.3.5)

$username=($_POST['username']);
$password=md5(md5($_POST['password'].$username)); 

$sqlcommand=" insert into tb_admin(username,password)Values('$username','$password')";

	$RS=mysql_query($sqlcommand);
	$result=mysql_num_rows($RS);

Imports System.Security.Cryptography
Imports System.Text

    Public Function MD5(ByVal strString As String) As String
        Dim ASCIIenc As New ASCIIEncoding
        Dim strReturn As String
        Dim ByteSourceText() As Byte = ASCIIenc.GetBytes(strString)
        Dim Md5Hash As New MD5CryptoServiceProvider
        Dim ByteHash() As Byte = Md5Hash.ComputeHash(ByteSourceText)
        For Each b As Byte In ByteHash
            strReturn = strReturn & b.ToString("x2")
        Next
        Return strReturn
    End Function

Imports System.Security.Cryptography
Imports System.Text

Imports System.Security.Cryptography
Imports System.Text

    Public Function MD5(ByVal strString As String) As String
        Dim ASCIIenc As New ASCIIEncoding
        Dim strReturn As String
        Dim ByteSourceText() As Byte = ASCIIenc.GetBytes(strString)
        Dim Md5Hash As New MD5CryptoServiceProvider
        Dim ByteHash() As Byte = Md5Hash.ComputeHash(ByteSourceText)

        strReturn = ""

        For Each b As Byte In ByteHash
            strReturn = strReturn & b.ToString("x2")
        Next
        Return strReturn
    End Function

Function MD5(sMessage)
	Dim x
	Dim k
	Dim AA
	Dim BB
	Dim CC
	Dim DD
	Dim a
	Dim b
	Dim c
	Dim d
	
	Const S11 = 7
	Const S12 = 12
	Const S13 = 17
	Const S14 = 22
	Const S21 = 5
	Const S22 = 9
	Const S23 = 14
	Const S24 = 20
	Const S31 = 4
	Const S32 = 11
	Const S33 = 16
	Const S34 = 23
	Const S41 = 6
	Const S42 = 10
	Const S43 = 15
	Const S44 = 21

	x = ConvertToWordArray(sMessage)
	
	a = &H67452301
	b = &HEFCDAB89
	c = &H98BADCFE
	d = &H10325476

	For k = 0 To UBound(x) Step 16
		AA = a
		BB = b
		CC = c
		DD = d
	
		FF a, b, c, d, x(k + 0), S11, &HD76AA478
		FF d, a, b, c, x(k + 1), S12, &HE8C7B756
		FF c, d, a, b, x(k + 2), S13, &H242070DB
		FF b, c, d, a, x(k + 3), S14, &HC1BDCEEE
		FF a, b, c, d, x(k + 4), S11, &HF57C0FAF
		FF d, a, b, c, x(k + 5), S12, &H4787C62A
		FF c, d, a, b, x(k + 6), S13, &HA8304613
		FF b, c, d, a, x(k + 7), S14, &HFD469501
		FF a, b, c, d, x(k + 8), S11, &H698098D8
		FF d, a, b, c, x(k + 9), S12, &H8B44F7AF
		FF c, d, a, b, x(k + 10), S13, &HFFFF5BB1
		FF b, c, d, a, x(k + 11), S14, &H895CD7BE
		FF a, b, c, d, x(k + 12), S11, &H6B901122
		FF d, a, b, c, x(k + 13), S12, &HFD987193
		FF c, d, a, b, x(k + 14), S13, &HA679438E
		FF b, c, d, a, x(k + 15), S14, &H49B40821
	
		GG a, b, c, d, x(k + 1), S21, &HF61E2562
		GG d, a, b, c, x(k + 6), S22, &HC040B340
		GG c, d, a, b, x(k + 11), S23, &H265E5A51
		GG b, c, d, a, x(k + 0), S24, &HE9B6C7AA
		GG a, b, c, d, x(k + 5), S21, &HD62F105D
		GG d, a, b, c, x(k + 10), S22, &H2441453
		GG c, d, a, b, x(k + 15), S23, &HD8A1E681
		GG b, c, d, a, x(k + 4), S24, &HE7D3FBC8
		GG a, b, c, d, x(k + 9), S21, &H21E1CDE6
		GG d, a, b, c, x(k + 14), S22, &HC33707D6
		GG c, d, a, b, x(k + 3), S23, &HF4D50D87
		GG b, c, d, a, x(k + 8), S24, &H455A14ED
		GG a, b, c, d, x(k + 13), S21, &HA9E3E905
		GG d, a, b, c, x(k + 2), S22, &HFCEFA3F8
		GG c, d, a, b, x(k + 7), S23, &H676F02D9
		GG b, c, d, a, x(k + 12), S24, &H8D2A4C8A
			
		HH a, b, c, d, x(k + 5), S31, &HFFFA3942
		HH d, a, b, c, x(k + 8), S32, &H8771F681
		HH c, d, a, b, x(k + 11), S33, &H6D9D6122
		HH b, c, d, a, x(k + 14), S34, &HFDE5380C
		HH a, b, c, d, x(k + 1), S31, &HA4BEEA44
		HH d, a, b, c, x(k + 4), S32, &H4BDECFA9
		HH c, d, a, b, x(k + 7), S33, &HF6BB4B60
		HH b, c, d, a, x(k + 10), S34, &HBEBFBC70
		HH a, b, c, d, x(k + 13), S31, &H289B7EC6
		HH d, a, b, c, x(k + 0), S32, &HEAA127FA
		HH c, d, a, b, x(k + 3), S33, &HD4EF3085
		HH b, c, d, a, x(k + 6), S34, &H4881D05
		HH a, b, c, d, x(k + 9), S31, &HD9D4D039
		HH d, a, b, c, x(k + 12), S32, &HE6DB99E5
		HH c, d, a, b, x(k + 15), S33, &H1FA27CF8
		HH b, c, d, a, x(k + 2), S34, &HC4AC5665
	
		II a, b, c, d, x(k + 0), S41, &HF4292244
		II d, a, b, c, x(k + 7), S42, &H432AFF97
		II c, d, a, b, x(k + 14), S43, &HAB9423A7
		II b, c, d, a, x(k + 5), S44, &HFC93A039
		II a, b, c, d, x(k + 12), S41, &H655B59C3
		II d, a, b, c, x(k + 3), S42, &H8F0CCC92
		II c, d, a, b, x(k + 10), S43, &HFFEFF47D
		II b, c, d, a, x(k + 1), S44, &H85845DD1
		II a, b, c, d, x(k + 8), S41, &H6FA87E4F
		II d, a, b, c, x(k + 15), S42, &HFE2CE6E0
		II c, d, a, b, x(k + 6), S43, &HA3014314
		II b, c, d, a, x(k + 13), S44, &H4E0811A1
		II a, b, c, d, x(k + 4), S41, &HF7537E82
		II d, a, b, c, x(k + 11), S42, &HBD3AF235
		II c, d, a, b, x(k + 2), S43, &H2AD7D2BB
		II b, c, d, a, x(k + 9), S44, &HEB86D391
	
		a = AddUnsigned(a, AA)
		b = AddUnsigned(b, BB)
		c = AddUnsigned(c, CC)
		d = AddUnsigned(d, DD)
	Next
	
	MD5 = LCase(WordToHex(a) & WordToHex(b) & WordToHex(c) & WordToHex(d))
End Function

using System.Security.Cryptography;
public static string MD5HashCryptography(string string2Md5)
    {
            MD5 md5 = MD5CryptoServiceProvider.Create();

            byte[] dataMd5 = md5.ComputeHash(Encoding.Default.GetBytes(string2Md5));

            StringBuilder sb = new StringBuilder();

            for (int i = 0; i < dataMd5.Length; i++)
            {
                sb.AppendFormat("{0:x2}", dataMd5[i]);
            }

            string2Md5 = sb.ToString();

            return string2Md5;
    }