固定文字说明的导航

下面为效果显示

脚本说明:
把如下代码加入<body>区域中
<script language="JavaScript" type="text/javascript">

function lib_bwcheck(){ //Browsercheck (needed)
	this.ver=navigator.appVersion
	this.agent=navigator.userAgent
	this.dom=document.getElementById?1:0
	this.opera5=this.agent.indexOf("Opera 5")>-1
	this.ie5=(this.ver.indexOf("MSIE 5")>-1 && this.dom && !this.opera5)?1:0; 
	this.ie6=(this.ver.indexOf("MSIE 6")>-1 && this.dom && !this.opera5)?1:0;
	this.ie4=(document.all && !this.dom && !this.opera5)?1:0;
	this.ie=this.ie4||this.ie5||this.ie6
	this.mac=this.agent.indexOf("Mac")>-1
	this.ns6=(this.dom && parseInt(this.ver) >= 5) ?1:0; 
	this.ns4=(document.layers && !this.dom)?1:0;
	this.bw=(this.ie6 || this.ie5 || this.ie4 || this.ns4 || this.ns6 || this.opera5)
	return this
}
var bw=new lib_bwcheck()

if(document.layers){ //NS4 resize fix...
	scrX= innerWidth; scrY= innerHeight;
	onresize= function(){if(scrX!= innerWidth || scrY!= innerHeight){history.go(0)} }
}

/****
Variables to set 
****/
msgFont= "arial,helvetiva"	// The font for the message
msgFontSize= 12				// Set the fontSize in px
msgFontColor="#000000"		// Set the fontColor
msgWidth= "300"				// Set the width of the messageblock here for netscape 4

//Set the text you want to display on mouseover here.
messages=new Array()
messages[0]="" //This is the default text that appears when you mouse out.
messages[1]="这里是链接一的说明内容"
messages[2]="这里是链接二的说明内容"
messages[3]="This link however, nr3, isn't that good..."
messages[4]="Maybe you should try this one?<br>I'll write some more text to show that it wraps correctly to several lines."
messages[5]="这里是链接五的说明内容"
messages[6]="Later all.."

/********************************************************************************
You don't have to change anything below this
********************************************************************************/

//ChangeText object constructor.
function makeChangeTextObj(obj){
   	this.css = bw.dom?document.getElementById(obj).style:bw.ie4?document.all[obj].style:bw.ns4?document.layers[obj]:0;	
   	this.writeref = bw.dom?document.getElementById(obj):bw.ie4?document.all[obj]:bw.ns4?document.layers[obj].document:0;	
	this.writeIt = b_writeIt;					
}
function b_writeIt(text,num){
	if (bw.ns4){
		this.writeref.write(text)
		this.writeref.close()
	}
    else this.writeref.innerHTML = messages[num]
}

//The mouoseover function. Calls the writeIt method to write the text to the div.
function changeText(num){
	if(bw.bw) oMessage.writeIt('<table width="'+msgWidth+'" border="0" cellpadding="0" cellspacing="0"><tr><td><span style="font-size:'+msgFontSize+'px; font-family:'+msgFont+'; color:'+msgFontColor+'">'+messages[num]+'</span></td></tr></table>', num)
}

//The init function. Calls the object constructor and initiates some properties.
function changeTextInit(){
	//Fixing the browsercheck for opera... this can be removed if the browsercheck has been updated!!
	bw.opera5 = (navigator.userAgent.indexOf("Opera")>-1 && document.getElementById)?true:false
	if (bw.opera5) bw.ns6 = 0
	
	oMessage = new makeChangeTextObj('divMessage')
	oLinks = new makeChangeTextObj('divLinks')
	//Setting the style properties of the text layer.
	if(bw.dom || bw.ie4){
		with(oMessage.writeref.style){fontFamily=msgFont; fontSize=msgFontSize+"px"; color=msgFontColor}
	}
	//Both layers are hidden by default to prevent users from mousing over them and creating errors while the page loads.
	oMessage.css.visibility= "visible"
	oLinks.css.visibility= "visible"
}

//If the browser is ok, the init function is called on pageload. 
if (bw.bw) onload = changeTextInit
</script>
<div id="divLinks">
<a href="#" onmouseover="changeText(1)" onmouseout="changeText(0)">链接一</a>
<a href="#" onmouseover="changeText(2)" onmouseout="changeText(0)">链接二</a>
<a href="#" onmouseover="changeText(3)" onmouseout="changeText(0)">链接三</a>
<a href="#" onmouseover="changeText(4)" onmouseout="changeText(0)">链接四</a>
<a href="#" onmouseover="changeText(5)" onmouseout="changeText(0)">链接五</a>
<a href="#" onmouseover="changeText(6)" onmouseout="changeText(0)">链接六</a>
</div>
<div id="divMessage">