17-2.txt

Javascript语言开发经典教程开发

<STYLE TYPE="text/javascript">
// This is regular JavaScript code, running in the scope of the Document.

/* Specify that headings display in blue italic text. */
tags.H1.color = tags.H2.color = "blue";
tags.H1.fontStyle = tags.H2.fontStyle = "italic";

/* 
 * Any element of CLASS="WARNING" displays in bold on an 
 * indented yellow background with a fat red border.
 */
classes.WARNING.all.fontWeight = "bold"
classes.WARNING.all.backgroundColor = "yellow";
classes.WARNING.all.marginLeft = "1in";
classes.WARNING.all.marginRight = "1in";
classes.WARNING.all.borderWidth = "8px";
classes.WARNING.all.borderStyle = "solid";
classes.WARNING.all.borderColor = "red";

/*
 * A H1 or H2 heading within an element with CLASS="WARNING" 
 * should be centered, in addition to appearing in blue italics.
 */
contextual(classes.WARNING.all, tags.H1).textAlign = "center";
contextual(classes.WARNING.all, tags.H2).textAlign = "center";

/* The single element with ID="P23" displays in centered uppercase. */
ids.P23.textAlign = "center";
ids.P23.textTransform = "uppercase";
</STYLE>

<SCRIPT>
// We can also specify styles in regular SCRIPT tags, but here we
// have to explicitly specify the Document object. Also, it is only
// meaningful to write style properties in the HEAD of the document
// before any text has been formatted and output.
document.ids.P23.color = "green";

// Style objects behave just like other objects, and we can read
// style properties from them.
var style = document.classes.WARNING.all, s = "";
for (i in style) s += i + ": " + style[i] + "\n";
alert(s);
</SCRIPT>