Encrypt value in Javascript & decrypt in serverside(C#)

 public static bool ValidateQueryString(string password, string saltedHash) {
        //  Extract hash and salt string
        string saltString = saltedHash.Substring((saltedHash.Length - 24));
        string hash1 = saltedHash.Substring(0, (saltedHash.Length - 24));
        //  Append the salt string to the password
        string saltedPassword = (password + saltString);
        //  Hash the salted password
        string hash2 = FormsAuthentication.HashPasswordForStoringInConfigFile(saltedPassword, "SHA1");
        //  Compare the hashes
        return (hash1.CompareTo(hash2) == 0);
    }

<%@ Import Namespace="System.Security.Cryptography" %>
<%@ Import Namespace="System.Text" %>
<script language="VB" runat="server">
  Sub DisplayEncryptedText(sender as Object, e as EventArgs)
    If Page.IsValid then
      Dim md5Hasher as New MD5CryptoServiceProvider()
    
      Dim hashedDataBytes as Byte()   
      Dim encoder as New UTF8Encoding()

      hashedDataBytes = md5Hasher.ComputeHash(encoder.GetBytes(txtPassword.Text))    
    
      ltlResults.Text = "<b>Encrypted Results</b><br /> The results are encrypted into " & _
              "an array of 16 bytes.  These 16 bytes contain the values:<p><ul>"
    
      Dim b as Byte
      For Each b in hashedDataBytes
	    ltlResults.Text &= "<li>" & b & "</li>"
      Next b
      
      ltlResults.Text &= "</ul>"    
    End If
  End Sub  
</script>

<form runat="server">
  Enter a string:
  <asp:TextBox id="txtPassword" runat="server" />
  <asp:RequiredFieldValidator runat="server" ControlToValidate="txtPassword"
           Display="Dynamic" ErrorMessage="<i>You must provide a value here...</i>" />
  <asp:RegularExpressionValidator runat="server" ControlToValidate="txtPassword"
           Display="Dynamic" ErrorMessage="<i>The string must be 20 characters or less...</i>"
           ValidationExpression="^.{1,20}$" />
  <br />
  <asp:Button runat="server" Text="View the String as Encrypted Text"
	OnClick="DisplayEncryptedText" />
  <p>
  <asp:Literal runat="server" id="ltlResults" />
</form>