Whether it’s because you have made a call using a mobile phone, received a message on your pager, checked your email from a PDA or even just seen an advert related to it, we have all come across a wireless data or voice network!If a user, application or company wishes to make data portable, mobile and accessible then wireless networking is the answer. A wireless networking system would rid of the downtime you would normally have in a wired network due to cable problems. It would also save time and money due to the fact that you would spare the expense of installing a lot of cables. Also, if a client computer needs to relocate to another part of the office then all you need to do is move the machine with the wireless network card.

An SMTP (Simple Mail Transfer Protocol) server is a machine that transports mail, just like a Web server is a machine that displays Web pages when requested. An SMTP server is sometimes referred to as an outgoing mail server, which brings me to the point—you need one in order to complete the exercises in this chapter. On Linux/UNIX, Sendmail and Qmail are popular packages. On Windows, the SMTP service in the Windows NT Service Pack, or the service built into the Windows 2000 operating system, is typically used.

We saw at the beginning of this section that one way to embed client-side JavaScript into HTML documents is to use event handler attributes of HTML tags. The following table lists the standard event handler attributes and the HTML tags to which they may be applied. The first column of the table gives the event handler attribute name: these names always begin with "on". The second column of the table lists the HTML tags to which these attributes can be applied, and explains, when necessary, what events trigger the handler code to be executed.

If you write macros that other people in your organization use, you should be aware of the Macro Security settings in Excel (and in all Office applications). These settings control the messages you receive when you open a workbook that contains macros; they ask if it’s okay to enable them. In the good old days, developers didn’t have to worry about such things. But with the advent of macro viruses, you now need to take such user-level security settings into account when developing code. In Office 2000/XP, there are three levels of security for macros contained within files: