17-3.txt

Javascript语言开发经典教程开发

<!-- Here's some HTML.  We're going to animate the color of the named H1. -->
<DIV CLASS="WARNING">
<H2 ID="WARNING1" STYLE="color:red; text-align:center">Red Alert!</H2>
The Web server is on fire!
</DIV>

<SCRIPT>
// Animate the color of the element with ID="WARNING1", by 
// setting properties of its style object every half second.
var colors = ["red", "orange", "black"];  // Cycle through these colors.
var nextcolor = 0;

// Invoke this function to change to the next color.
function changecolor() {
    document.all.WARNING1.style.color = colors[nextcolor++];
    nextcolor = nextcolor % colors.length;
}

// Arrange to call changecolor() every half second.
setInterval("changecolor()", 500);
</SCRIPT>