Chúng tôi cũng sẽ tạo ra padding trong các hộp bằng cách đưa ra các tài sản padding một giá trị của 1%. Bởi vì padding được thêm vào chiều rộng của hộp, để tạo ra một hộp thoại mà chiếm 30% của màn hình, các thuộc tính chiều rộng cho mỗi cột cần phải có một giá trị | Chapter 11 Learning JavaScript You can see this page in Figure 11-4. Figure 11-4 The DOM would allow a script to access The content of the form as part of the forms collection The two links as part of the links collection Accessing Values Using Dot Notation In order to access the different objects in the DOM you list the objects in the tree shown in Figure 11-3 starting with the document object working down to the object that holds the data you are after. Each object is separated by a period or full-stop character hence this is known as a dot notation. For example in order to access the first link in the document you would want the links object which is a child of the document object so you could use something like this 0 .href There are four parts of this statement three of which are separated by periods to get to the first link The word document indicates I am accessing the document object. The word links corresponds to the links collection after all this example is to retrieve the value of the first link in the document . The 0 indicates that I want the first link in the document. Rather confusingly the items of a collection are numbered from 0 rather than 1 which means the second link in the links collection is represented using 1 the third using 2 and so on. I have indicated that I want to retrieve the href property for this link. Each object has different properties that correspond to that type of element for example links have properties such as the href property that accesses the value of the href attribute on this a element. Similarly a textarea object has properties such as cols disabled readOnly and rows which correspond to the attributes on that element. 490 Chapter 11 Learning JavaScript Rather than using the names of the type of object such as forms and links you can use the value of name attributes on the elements to navigate through the document. For example the following line requests the value of the password box .
