Many CGI programs, such as guestbook programs, require that only one user at a time be allowed to access a data file. You can lock a file with the Perl

Users of Visual InterDev 6 have reported frustrating problems in configuring their data connections while using the Data Environment (DE). Even though you manually edit the Application variables and connection

There are three ways to deal with checked exceptions in Java. First, you can declare that the “callee” method throws them (using the “throws” keyword). You should do this when

Question: How do I make the mouse click in VB 4? It just auto clicks without user inputs in the spot the mouse currently is. Answer: Without having to go

Question: I use ADO with an Oracle database. To get the connection I have to use: dim Adodb as New ADODB.connectionwith Adodb .connectionString = ???? .openend with What do I

Question: I’m a beginner to Visual Basic, and I would like to display in a text box several lines of text. However, when I enter the code under the command

Question: When a textbox or combo box is disabled, the black text within these control becomes grey. I would like to have all the features of disabling these controls, but

If you have the same JavaScript program appearing on several different Web pages, you might want to consider using an external file. That way all the pages can refer to

You accomplish basic file I/O in Java using data streams. The most basic file I/O operations in Java use the functionality offered by these classes: FileInputStreamFileOutputStream If you’re new to

There are several situations when you need to retain the state of a flag between different instances in a program. The standard way to do this is to declare the

You can use the generic algorithm find() to locate an element of a container. The find() algorithm takes three arguments. The first two are iterators that point at the beginning

C and C++ define NULL differently: #define NULL 0; // A typical definition of NULL in C++ #define NULL ((void*)0) // C defines NULL this way Why is it defined

Although most Web servers give you the option of allowing users to view the list of files in a Web site directory, you may not want to show some types

Question: I want to add a simple form to my Web page, but I can’t figure it out. I want a form that lets my users enter text into a

Nested namespaces are useful in large-scale projects, whereby every development team gets a dedicated namespace within the project’s namespace. Nested namespaces reduce the likelihood of name clashes among different teams

The JSlider component can be customized so that its labels, track, and tickmarks (or any combination of the three) are hidden. Unfortunately, there’s no way to turn off the slider

Hide your navigation buttons using DHTML when you don’t need them. Imagine a page with a databound table on it showing ten rows of data. When you’re at the beginning

The Visual Basic Snapshot data object is closely related to the Dynaset data object, but differs in several key respects. Snapshots are stored entirely in RAM on the user’s local

All SQL-compliant systems, including Microsoft JET SQL, have a set of functions to return computed results of numeric data stored in a column. All the aggregate functions create effects that

All of the aggregate components in Swing–that is, components made up other components, such as JTable, JTree, or JComboBox–can be highly customized. For example, a JTable component normally displays a

Environment variables are useful for gathering data about a client’s system settings, but different servers have different environment variables available to them. To find out what environment variables are available

Question: I developed a Web site with a database on my machine using Internet Information Server (IIS), Active Server Pages (ASP), and SQL Server. I want to install the site,

Question: What HTML tag do I use to have the screen refresh every two minutes? Answer: The following META tag will work. The value of the CONTENT parameter will determine

Question: I am designing a Web site for a conference. Over 2000 attendees are going to use the Web site for registering online, as well as for other interactive tasks,

Question: I am building Web pages using Visual Basic 6, Web Classes, HTML, DHTML, and JavaScript. Do you know of any good books that actually explain this type of programming?

Question: We have one phone line coming into the house. How can I get the phone to ring and the Internet connection to be broken if I’m on the net

Question: Can I use two submit buttons in the same form, but refer to two different scripts? Answer: Yes, it is possible to add two submit buttons to an HTML

In general, API functions and classes enable you to interact with the operating system. Sometimes, however, it is much simpler to execute a system command directly. For this purpose, you

When developing a database program, always keep the data-input user in mind. The most elegant program in the world is useless if the data is riddled with errors. If a

You can initialize a vector with the contents of a built-in array like this: #include#include using namespace std;int main(){ int arr[3]; arr[0] = 4; arr[1] = 8; arr[2] = 16;