/* This the style sheet used for TimetableAssistanWeb version - similar but different from regular style */ /* This Is Style of Sheets at NesterenkoSoftware.com */ /* Changes Made: Added table.QuakerAlt tr.D2 td { For Total Line */ /* ids must be unique where as class can be applied to many things. In CSS, ids look like #elementID and class elements look like .someClass In general, use id whenever you want to refer to a specific element and class when you have a number of things that are all alike. For instance, common id elements are things like header, footer, sidebar. Common class elements are things like highlight or external-link. It's a good idea to read up on the cascade and understand the precedence assigned to various selectors: http://www.w3.org/TR/CSS2/cascade.html The most basic precedence you should understand, however, is that id selectors take precedence over class selectors. If you had this:

Hello!

and: #intro { color: red } .foo { color: blue } The text would be red because the id selector takes precedence over the class selector. Where to use an ID versus a class The simple difference between the two is that while a class can be used repeatedly on a page, an ID must only be used once per page. Therefore, it is appropriate to use an ID on the div element that is marking up the main content on the page, as there will only be one main content section. In contrast, you must use a class to set up alternating row colors on a table, as they are by definition going to be used more than once. IDs are an incredibly powerful tool. An element with an ID can be the target of a piece of JavaScript that manipulates the element or its contents in some way. The ID attribute can be used as the target of an internal link, replacing anchor tags with name attributes. Finally, if you make your IDs clear and logical, they can serve as a sort of “self documentation” within the document. For example, you do not necessarily need to add a comment before a block stating that a block of code will contain the main content if the opening tag of the block has an ID of, say, "main", "header", "footer", etc. An id must be unique in the whole page. A class may apply to many elements. Sometimes, it's a good idea to use ids. In a page, you usually have one footer, one header... Then the footer may be into a div with an id