Appendix J Introduction to HyperText Markup (Web site layout) Language 4:
Appendix J Introduction to HyperText Markup Language 4: Part 2 1427 A coordinate pair consists of two numbers, which are the locations of the point on the x and y axes. The x axis extends horizontally from the upper-left corner, the y axis vertically. Every point on an image has a unique x y coordinate, annotated as (x, y). In the case of a rectangular hotspot, the required coordinates are those of the upper-left and lowerright corners of the rectangle. The shape=”poly” creates a hotspot of no preset shape you specify the shape of the hotspot in the coords attribute by listing the coordinates of every vertex, or corner of the hotspot. shape=”circle” creates a circular hotspot; it requires both the coordinates of the center of the circle and the length of the radius, in pixels. To use an image map with a graphic on your page, you must insert the usemap=”#name” attribute into the imgelement, where name is the value of the name attribute in the map element. The main element that interacts with search engines is the meta element. meta tags contain two attributes that should always be used. The first of these, name, is an identification of the type of meta tag you are including. The content attribute gives the information the search engine will be cataloging. The content of a meta tag with name=”keywords” provides the search engines with a list of words that describe the key aspects of your site. By including meta tags and their content information, you can give precise information about your site to search engines. This will help you draw a more focused audience to your site. The descriptionvalue of the nameattribute in the metatag should be a 3-to-4-line description of your site, written in sentence form. This description is used by the search engine to catalog and display your site. meta elements are not visible to users of the site and should be placed inside the header section of your HTML document. The frameset tag tells the browser that the page contains frames. colsor rows gives the width of each frame in pixels or as a percentage of the screen. In each frame element, the srcattribute gives the URL of the page that will be displayed in the specified frame. The purpose of a name attribute in the frame element is to give an identity to that specific frame, in order to enable hyperlinks in a frameset to load their intended frame. The target attribute in an anchor element is set to the name of the framein which the new page should load. A target in an anchor element can be set to a number of preset values: target=”_blank” loads the page in a new blank browser window, target=”self” loads the page into the same window as the anchor element, target=”_parent” loads the page into the parent frameset and target=”_top” loads the page into the full browser window. Not everyone viewing a page has a browser that can handle frames. You therefore need to include a noframes element inside of the frameset. You should include regular HTML tags and elements within the