Packets sent to an ordinary web site (one with an http://.... address) could be intercepted, and since they would be "in the clear" this is what makes people say that it is not safe to send credit card information via the Internet. However there are sites called "Secure Servers", which have an https://..... address, and if your browser supports these secure servers, then it should be perfectly safe to send credit card information via the internet to a secure server, since all messages to and from the server are encrypted. Using 40-bit key size for RC4 streem encryption, it would take on the average 64 MIPS-years to break such an encrypted message (a computer capable of 64 million instructions per second would take a year to break the code).

But how can you tell whether you are on a secure server? Using Netscape Navigator, if the key symbol in the lower left corner of the screen has a break in it and is on a gray background you are on an unsecure web page, and if it is whole, and has a blue background, you are on a secure web page. The key has two teeth for high-grade encryption, and one tooth for medium-grade encryption. The location field will also show a URL that begins "https://" for secure servers, and "http://" for non-secure servers. In Netscape Communicator, and in Microsoft Internet Explorer, non-secure pages are indicated by an icon of a padlock that is unlocked, and secure pages are indicated by an icon of a padlock that is locked.

Netscape Navigator Unsecure	Netscape Navigator Secure
Netscape Communicator Unsecure	Internet Explorer Secure
https indicates secure server

With Netscape click on Options, and locate the Auto Load Images entry. If it has a check mark beside it, images will automatically be downloaded. If the entry does not have a check mark, images will not automatically be downloaded. To change the check mark to no check mark, or no check mark to check mark, position the mouse on the Auto Load Images line and click.

If you have Auto Load Images turned off, the images will not be downloaded, and instead you will get a little rectangular box with a symbol that has a question mark in it, and several other graphical elements like triangles, and the upper right corner is folded down. If you want a single image locate the symbol for that image and click it. If you want all of the images for a particular page, locate the box "Images" on the tool bar and click it. That box is greyed out when you have Auto Load Images turned on, but it becomes active when you turn Auto Load Images off.

In Microsoft Internet Explorer for 3.1, images not downloaded will be replaced by a box with an X in it.

Netscape Navigator

Internet Explorer 3.1

The pages that bring up their text quickly are properly designed, and they indicate the width and height of images, so the browser will know how to format the page, even before the image is downloaded. Images that do not include this width and height specification must be downloaded before the browser can format the page, and hence it cannot display the text until that happens.

In the Tulsa Computer Society web page, if we just had:

But how do I know how big my images are?

Many graphic programs, like photo shop, will show you the pixel width and height of an image. One program that you can use is LVIEW, discussed in the June issue of the I/O Port (http://www.tcs.org/ioport/lview.htm), and when you load an image, look in the title bar of the image, and you will see something like 400x205x64, which says that the image is currently sized to be 400 pixels wide by 205 pixels high and uses a 64 color pallet.

Include the ALT string in an IMG tag, and the text in the ALT string will be displayed instead of the image (for text-only browsers), or inside the box specified by the Width and Height Tags, unless and until the graphic image itself is downloaded. For example, the IMG tag from the TCS Web Page is actually:

The envelope is a Mail icon. You can click on the mail icon to display the Mail window (if not already open) and retrieve for new messages. The mail icon includes a question mark (?) if Netscape cannot automatically check the mail server for new messages. The mail icon includes an exclamation point if the news server has new messages for you.

For more information on the Tulsa Computer Society click here