The sin of pride in Web design is failing to consider how your design choices will affect your audience. It is important that you check your Web pages on both Netscape and IE for inconsistencies. Web pages can be interpreted differently by different versions of the same browser. Netscape 4.0 has some features that won't work at all in Netscape 3.0. So it is good practice to check your Web pages in as many versions and browsers as possible.
Web pages can look different on different computer platforms.
For example, Macs show fonts two point sizes smaller than PCs with the same point size specified. Also keep in mind that not everyone viewing your pages has the same physical advantages. Visually impaired individuals may be browsing your site with a text to speech reader. If you use mainly graphics on a page, the text to speech reader has no text to read. Make sure that you represent all important images with an alternative text attribute.