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Forward-Declaring a Namespace Member

Suppose you need to forward-declare class Interest, which is a member of namespace Bank. It would seem that all you need to do is use the class’s fully qualified name:

ActiveX Can’t Create Which Object?

When working on a large VB application that uses hundreds of COM objects, the “429 can’t create object” error doesn’t give you much help in determining which object could not

Real Time Programming: Myths and Reality

The term “real time” has become a buzzword, as in “real time stock quotes” or “real time database queries”. However, neither a database-oriented system nor a NYSE stock ticker running

Dynamic Versus Static Binding

Not every call of a virtual function is resolved dynamically. In fact, in many cases the compiler resolves the call statically, even if the function is declared virtual. For example:

Assign Toolbar Button Images at Run Time

When developing applications, quite often you end up experimenting with different toolbar icons to test how well they serve their purpose. If you change an icon in an ImageList, you

Count ASP Sessions

Question: I am trying to count the number of users (sessions opened) to a given app. It easy enough to increment an Application variable with Session_Onstart and decrement it with

Make Variable Available to All Pages

Question: Can I use a global variable in VBScript and make it accessible from any Web page? Answer: There is no such thing as a global variable in Web pages.

Find the Path of a Project With ASP

Question: Is there any way to programmatically determine the path of the current ASP page on the server? I am trying to access a specific text that I added to

Determine Which Submit Button Was Clicked

Question: I have a Web page with a form(action=sample.asp),frmProduct. The form has some textboxes (one of which is a key field, sav txtKey) and two submit buttons: one for retrieve

Reference a DLL From an ASP Page

Question: I wrote a DLL in Visual Basic and I want to use its functions in ASP. I created a server.CreateObject(“projectname.classname”) and tried to call some of the methods of

Get Count of Records in a Recordset

Question: How do I get the number of records from a “select * from dept where deptno = ..”? I want to know how many records are in my recordset

Leverage Office to Spellcheck RichText

Integrate Microsoft Word 97’s spellchecking capability into VB apps while maintaining formatting within a rich textbox. To test this code:1. Create a standard EXE project in VB.2. Add the RichTextBox

Handle Update Collisions in ADO Disconnected Recordsets

Data-access techniques using cached data on the client for updates is possible using disconnected recordsets. This technique generates collisions in some situations. However, the technique for dealing with collisions rows

Extracting a Number From a String

There are many applications that store numbers in strings that also contain text. For example, some databases store dates as strings in the form of “01Jan”. You can extract the

Run Time Object / Control Management

Question: Can I write statements to add/delete the control objects like command buttonsat runtime like we do in java C++ ? Iam under the assumption that once we populate a

Refresh Part of a Page

Question: Is there a way to refresh or redraw part of a screen display using HTML and JavaScript without using frames? I want the top 1/4 of my screen to

Nested Quotes and JavaScript

Question: I am trying to use document.writeln to write a table onto a floating menu bar. Part of the table cell’s events is Java code. When it reaches the semicolons

Set Font Size in Tables Using DHTML

Question: In Microsoft Internet Explorer, I can specify a style as TABLE.listTable { font-size : “10pt”} and all the cells of the table will have a 10pt font size. In

Preserve the Format of Text/Memo Fields

Question: We are doing a small site with some ASP content. When we get data from a memo field that has CR/LFs at the end of the lines for formatting

Abstract Classes

Question: Can I instantiate an abstract class? Answer: No, you cannot instantiate an abstract class. However, you can declare a pointer or a reference to it: class Abs{public: virtual void

Display Contents of ADODB.Errors Collection

When ADO encounters an error, the Errors Collectionis filled with certain specific details on the causeof the error. You can check the Errors collection ofthe Connection object whenever you encounter

Always Use Option Explicit

You should always use Option Explicit statement in your .asp file. Thisstatement will enforce that you explicitly declare all the variables in thescript. The whole problem: VBScript allows you to

Always Prefer to Use Local Variables

You should always prefer to use Local variables. Local variables reside within functions and subs. They have local scope and limited lifetime. These variables are compiled into numeric references and

Display Greeting Message

Here is a simple way by which you can display a greeting message to a user at the time of login.There are certain scenarios where you can use thisfeature to

How to Instantiate a Template Correctly

The type that a template takes as an argument must have external linkage. This means that you cannot instantiate a template with a locally-declared type: int main(){ struct S {

What’s in a Signature?

A function’s signature consists of the function’s parameter list and the parameters’ ordering. A member function’s signature also includes the const/volatile qualifiers (if any) of that function. Signatures provide the

Determining Size of an INPUT Field

Question: How can I determine the maximum size of an INPUT field? Answer: Although you can certainly use JavaScript to find out the size of your user’s screen or the