ASP.NET

<asp:TextBox ID="txtExchangePartQty" runat="server" onfocus="if(this.value==this.defaultvalue) this.value='';" value="Quantity..."  Width="120px">
               </asp:TextBox>
               <asp:FilteredTextBoxExtender ID="ftbeQty" runat="server" TargetControlID="txtExchangePartQty" ValidChars="1234567890" />

<tr>
      <td>
            <asp:AsyncFileUpload ID="ImageUploader" runat="server" 
                                    UploaderStyle="Modern" ThrobberID="myThrobber"
                                    UploadingBackColor="Yellow" 
                                    CompleteBackColor="Green" ErrorBackColor="Red" />
      </td>
      <td>
            <asp:Image ID="myThrobber" runat="server" ImageUrl="~/Images/uploading.gif"
                          Visible="true" />
      </td>
</tr>

Dim bufferLen As Integer = 8040
Dim br As BinaryReader = New BinaryReader(ImageUploader.FileContent)
Dim chunk As Byte() = br.ReadBytes(bufferLen)

minRequiredPasswordLength="6"
minRequiredNonalphanumericCharacters="0"

<asp:Label ID="PasswordLabel" runat="server" AssociatedControlID="Password">Password:</asp:Label>
<asp:TextBox ID="Password" runat="server" CssClass="passwordEntry" TextMode="Password"></asp:TextBox>
<asp:CustomValidator ID="CustomValidator_PW" runat="server" ControlToValidate="Password"
    OnServerValidate="CustomValidate_PW" ValidateEmptyText="true" Display="Dynamic"
    ErrorMessage="" ForeColor="Red" ValidationGroup="RegisterUser">
</asp:CustomValidator>
<asp:RequiredFieldValidator ID="PasswordRequired" runat="server" ControlToValidate="Password"
    CssClass="failureNotification" ErrorMessage="Password is required." ToolTip="Password is required."
    ValidationGroup="RegisterUser">*</asp:RequiredFieldValidator>

protected void CustomValidate_PW(object source, ServerValidateEventArgs args)
{
    CustomValidator cv = (CustomValidator)source;

    //check if password conforms to minimum password length
    string pw = RegisterUser.Password;
    if (pw.Length < Membership.MinRequiredPasswordLength)
    {
        cv.ErrorMessage = "Minimum Password length is " + Membership.MinRequiredPasswordLength;
        args.IsValid = false;
    }

    //check if password conforms to required number of nonAlphanumericCharacters
    if (Membership.MinRequiredNonAlphanumericCharacters > 0)
    {
        int count = 0;
        for (int j = 0; j < pw.Length; j++)
        {
            if (!char.IsLetterOrDigit(pw[j]))
            {
                count++;
            }
        }

        if (count < Membership.MinRequiredNonAlphanumericCharacters)
        {
            cv.ErrorMessage = "Password requires " + Membership.MinRequiredNonAlphanumericCharacters + " non-Aphanumeric characters";
            args.IsValid = false;
        }
    }
}