Using a text box and submit button, you can validate an e-mail address to make sure there is only one @ sign and that it is not at the beginning

On some occasions, the performance boost that can result from moving declarations is quite considerable. Consider this example: void use() { string s1; if (condition == false){ return; //s1 was

Java’s PipedInputStream and PipedOutputStream classes allow you to write data to an OutputStream object and to read this data from an InputStream object (see the tips “Pass Data Between Threads

Web authors should be used to using the ALT tag to provide a textual label for an image. However, you can’t apply ALT text to a textual link, and most

Objects are made serializable by implementing the java.io.Serializable interface. In general, when you serialize an object instance, all of the instance’s fields are considered to be part of its state,

A downcast is a cast from a base to a derived object. Before the introduction of RTTI to the language, downcasts were regarded as bad programming practice–they were unsafe and

A compiler can automatically optimize the code by unrolling loops. Consider this code: int *buff = new int[3]; for (int i =0; i

You may have used the tag to include ActiveX controls on your Web pages, but did you know that the tag can be used to include many other types of

When you create the visual components that make up a user interface, their size and position are usually constant. However, it’s sometimes necessary to change a component’s size or position

Question: I have two drop-down menus. How do I set a validation on my page so that users cannot go all the way to the server if they don’t select

Question: I have a page with two drop-downs and two corresponding radio buttons. When I choose an item from one drop-down, I’d like the corresponding radio button to become checked.

Question: I built a Web site for my company using FrontPage 98 and can not seem to upload it back to the Internet. I get error messages about server extensions.

VB5 provides interface inheritance through the use of the Implements keyword. For example, CFullTimeEmployee can implement the IEmployee interface. This interface might include basic information such as name, social security

Here’s a demo for using a Label control as a splitter between two controls, as well as sample code for employing the splitter in an Explorer-like application: Option ExplicitPrivate mbResizing

Select Case statements can lead to errors when the test expression in the Select Case line doesn’t yield a true result for any of its individual Case expressions. Therefore, you

Consider these two examples of code that add a string to a textbox. Example 1: Text1.text = Text1.text & MyString Text1.SelStart = Len(Text1.text) Example 2: Text1.SelStart = Len(Text1.text) Text1.SelText =

VB6 comes with an ActiveX control named MSWLESS.ocx (“Microsoft Windowless Controls 6.0”), which contains lightweight equivalents for these standard controls: WLTextWLFrameWLCommandWLCheckWLOptionWLComboWLListWLHScrollWHVScroll The controls have lower resource consumption than their regular

You’ll use the Format function most often with numbers, but it can be useful when applied to strings as well. For example, you can format a credit card number-which is

A POD (plain old data) object has one of these data types–a fundamental type, pointer, union, struct, array, or class–with no constructor. Conversely, a non-POD object is one for which

VBScript has two functions for adding/subtracting dates or date values: DateAdd and DateDiff. For example: DateAdd(interval, number, date)DateDiff(interval, date1, date2 [,firstdayofweek[, firstweekofyear]]) Interval could be “yyyy” for Year, “q” for

As you work with a VB project, the project file–VBP–can become littered with relative path references such as “……..myfoldermyform.frm”. The project loads, but only on your machine. If you send

An object’s behavior is defined by the operations that can be performed on it. This in turn translates to the methods defined in the object’s type or class. Java’s reflection

Sometimes, an event might fire while it’s already executing from a prior invocation. To prevent this unwanted behavior, assign a static variable within the procedure, and test it before allowing

Question: How many characters can fit in an alert box? Answer: There’s no way to tell how many characters can fit in an alert box. The size of the dialogs

Under some circumstances, the reference counting model can enhance performance in terms of both memory usage and speed. A reference counting class counts how many object instances have an identical

Before you spend too much time bashing your head against a problem in Active Server Pages or Visual InterDev, check to see if you’re not up against an acknowledged bug.

Question: I have a table with the following fields: Physician Patient # Procedure One of the Procedures is “X-ray.” How can I list the Patient # of anyone who has

‘ Replace placeholders in the form @@1, @@2, etc.’ with arguments passed after the first one.’ For example, calling this function with’ res = ReplaceArgs(“File @@1 not found on drive

‘ A variant of the Split function, that offers the following improvements’ You can pass a list of valid delimiters to the second argument’ (however, only single-char delimiters are accepted)’