the repeat-y option causes the image to repeat only vertically. Attachment: Use the attachment option to force a background image to its fixed position or to allow it to scroll along with the content. The scroll option is supported by Internet Explorer but not by Netscape. Horizontal and Vertical position: Use options from these menus to specify the initial position of the background image in relation to the element it's attached to. These options can be used to align a background image to the center of the page, both vertically and horizontally. If the Attachment property is Fixed, the position is relative to the Document window, not to the element. This property is supported by Internet Explorer but not by Netscape. Block Options The Block category of the CSS Rule Definition dialog, shown in Figure 7.14, provides you with the ability to define spacing and alignment settings for elements on your web pages. Figure 7.14. Use the Block category to modify spacing between paragraphs, lines of text, and more.   Here's a list of properties exposed by the Block category: Word spacing: Enter a value in this text box to set the spacing between words. After you've entered a value, you can choose one of the measurement options from the menu just to the right. Negative numbers are also allowed but the appearance depends on the browser. Letter spacing: Enter a value in this text box to increase (represented by a positive value) or decrease (represented by a negative value) space between letters or characters. Vertical alignment: Select an option from this menu to specify the vertical alignment of the element to which the class is applied. Dreamweaver displays this attribute in the Document window only when it is applied to an image. Text align: Sets the alignment of text on the page to left, right, center, or justify. Text indent: Enter a value in this text box to have the first line of text in your paragraph indent. You can also enter a negative number to outdent, but the appearance depends on the browser. Whitespace: Select an option from this menu to specify how white space within the selected element is handled. Options in this menu include Normal, Pre, and Nowrap. Choose Normal to collapse whitespace. Choose Pre to retain all whitespace, including spaces, tabs, and returns. Choose Nowrap to specify that text wraps only when a line break (<br>) is encountered. Display: Choose an option from this menu to specify whether an element is displayed and, if so, how it is displayed. There are too many options in this list to explain them all here. For more information, refer to one of the CSS resources presented in Appendix C, "General Resources." Box Options The Box category of the CSS Rule Definition dialog, shown in Figure 7.15, provides you with the ability to change and customize attributes in tables and the page itself. If you need to modify the width, height, padding, and spacing for a table, row, or cell, you would modify elements in this category. Furthermore, you can set the margins for the page by using the margin properties in this category. Figure 7.15. Use the Box category to modify width, height, padding, and spacing for tables, rows, and cells.   Here is a list of properties exposed by the Box category: