Só java script: Link com janela(passe o mouse sobre o link e aparece uma previa)

<head>
 <style>
 #PCL {
 		font-family: Verdana,Arial,Helvetica;
 		font-style: none;
 		font-weight: normal;
 		text-decoration: none;
 		font-size: 8pt;
 }
 
 #PTT {
 		font-family: Verdana,Arial,Helvetica;
 		font-size: 8pt;
 }
 
 #PST {
 		font-family: Verdana,Arial,Helvetica;
 		font-size: 8pt;
 }
 </style>
 </head>
 <body>
 </body>
 </html>
 <div id="overDiv" style="position:absolute; visibility:hide; z-index:1;"></div>
 <script language="JavaScript">
 ////////////////////////////////////////////////////////////////////////////////////
 // CONFIGURATION
 ////////////////////////////////////////////////////////////////////////////////////
 
 // Main background color (the large area)
 // Usually a bright color (white, yellow etc)
 	if (typeof fcolor == 'undefined') { var fcolor = "#CCCCFF";}
 	
 // Border color and color of caption
 // Usually a dark color (black, brown etc)
 	if (typeof backcolor == 'undefined') { var backcolor = "#333399";}
 	
 	
 // Text color
 // Usually a dark color
 	if (typeof textcolor == 'undefined') { var textcolor = "#000000";}
 	
 // Color of the caption text
 // Usually a bright color
 	if (typeof capcolor == 'undefined') { var capcolor = "#FFFFFF";}
 	
 // Color of "Close" when using Sticky
 // Usually a semi-bright color
 	if (typeof closecolor == 'undefined') { var closecolor = "#9999FF";}
 	
 	
 // Width of the popups in pixels
 // 100-300 pixels is typical
 	if (typeof width == 'undefined') { var width = "200";}
 	
 // How thick the border should be in pixels
 // 1-3 pixels is typical
 	if (typeof border == 'undefined') { var border = "1";}
 	
 	
 // How many pixels to the right/left of the cursor to show the popup
 // Values between 3 and 12 are best
 	if (typeof offsetx == 'undefined') { var offsetx = 10;}
 	
 // How many pixels to the below the cursor to show the popup
 // Values between 3 and 12 are best
 	if (typeof offsety == 'undefined') { var offsety = 10;}
 	
 ////////////////////////////////////////////////////////////////////////////////////
 // END CONFIGURATION
 ////////////////////////////////////////////////////////////////////////////////////
 
 ns4 = (document.layers)? true:false;
 ie4 = (document.all)? true:false;
 
 // Microsoft Stupidity Check.
 if (ie4) {
 	if (navigator.userAgent.indexOf('MSIE 5')>0) {
 		ie5 = true;
 	} else {
 		ie5 = false; }
 } else {
 	ie5 = false;
 }
 
 var x = 0;
 var y = 0;
 var snow = 0;
 var sw = 0;
 var cnt = 0;
 var dir = 1;
 var tr = 1;
 if ( (ns4) || (ie4) ) {
 	if (ns4) over = document.overDiv;
 	if (ie4) over = overDiv.style;
 	document.onmousemove = mouseMove;
 	if (ns4) document.captureEvents(Event.MOUSEMOVE);
 }
 
 // Public functions to be used on pages.
 
 // Simple popup right
 function drs(text) {
 	dts(1,text);
 }
 
 // Caption popup right
 function drc(text, title) {
 	dtc(1,text,title);
 }
 
 // Sticky caption right
 function src(text,title) {
 	stc(1,text,title);
 }
 
 // Simple popup left
 function dls(text) {
 	dts(0,text);
 }
 
 // Caption popup left
 function dlc(text, title) {
 	dtc(0,text,title);
 }
 
 // Sticky caption left
 function slc(text,title) {
 	stc(0,text,title);
 }
 
 // Simple popup center
 function dcs(text) {
 	dts(2,text);
 }
 
 // Caption popup center
 function dcc(text, title) {
 	dtc(2,text,title);
 }
 
 // Sticky caption center
 function scc(text,title) {
 	stc(2,text,title);
 }
 
 // Clears popups if appropriate
 function nd() {
 	if ( cnt >= 1 ) { sw = 0; };
 	if ( (ns4) || (ie4) ) {
 		if ( sw == 0 ) {
 			snow = 0;
 			hideObject(over);
 		} else {
 			cnt++;
 		}
 	}
 }
 
 // Non public functions. These are called by other functions etc.
 
 // Simple popup
 function dts(d,text) {
 	txt = "<TABLE WIDTH="+width+" BORDER=0 CELLPADDING="+border+" CELLSPACING=0 BGCOLOR=\""+backcolor+"\"><TR><TD><TABLE WIDTH=100% BORDER=0 CELLPADDING=2 CELLSPACING=0 BGCOLOR=\""+fcolor+"\"><TR><TD>"+text+"</TD></TR></TABLE></TD></TR></TABLE>";
 	layerWrite(txt);
 	dir = d;
 	disp();
 }
 
 // Caption popup
 function dtc(d,text, title) {
 	txt = "<TABLE WIDTH="+width+" BORDER=0 CELLPADDING="+border+" CELLSPACING=0 BGCOLOR=\""+backcolor+"\"><TR><TD><TABLE WIDTH=100% BORDER=0 CELLPADDING=0 CELLSPACING=0><TR><TD>"+title+"</TD></TR></TABLE><TABLE WIDTH=100% BORDER=0 CELLPADDING=2 CELLSPACING=0 BGCOLOR=\""+fcolor+"\"><TR><TD>"+text+"</TD></TR></TABLE></TD></TR></TABLE>";
 	layerWrite(txt);
 	dir = d;
 	disp();
 }
 
 // Sticky
 function stc(d,text, title) {
 	sw = 1;
 	cnt = 0;
 	txt = "<TABLE WIDTH="+width+" BORDER=0 CELLPADDING="+border+" CELLSPACING=0 BGCOLOR=\""+backcolor+"\"><TR><TD><TABLE WIDTH=100% BORDER=0 CELLPADDING=0 CELLSPACING=0><TR><TD>"+title+"</TD><TD ALIGN=RIGHT><A HREF=\"/\" onMouseOver=\"cClick();\" ID=\"PCL\">Close</A></TD></TR></TABLE><TABLE WIDTH=100% BORDER=0 CELLPADDING=2 CELLSPACING=0 BGCOLOR=\""+fcolor+"\"><TR><TD>"+text+"</TD></TR></TABLE></TD></TR></TABLE>";
 	layerWrite(txt);
 	dir = d;
 	disp();
 	snow = 0;
 }
 
 // Common calls
 function disp() {
 	if ( (ns4) || (ie4) ) {
 		if (snow == 0) 	{
 			if (dir == 2) { // Center
 				moveTo(over,x+offsetx-(width/2),y+offsety);
 			}
 			if (dir == 1) { // Right
 				moveTo(over,x+offsetx,y+offsety);
 			}
 			if (dir == 0) { // Left
 				moveTo(over,x-offsetx-width,y+offsety);
 			}
 			showObject(over);
 			snow = 1;
 		}
 	}
 // Here you can make the text goto the statusbar.
 }
 
 // Moves the layer
 function mouseMove(e) {
 	if (ns4) {x=e.pageX; y=e.pageY;}
 	if (ie4) {x=event.x; y=event.y;}
 	if (ie5) {x=event.x+document.body.scrollLeft; y=event.y+document.body.scrollTop;}
 	if (snow) {
 		if (dir == 2) { // Center
 			moveTo(over,x+offsetx-(width/2),y+offsety);
 		}
 		if (dir == 1) { // Right
 			moveTo(over,x+offsetx,y+offsety);
 		}
 		if (dir == 0) { // Left
 			moveTo(over,x-offsetx-width,y+offsety);
 		}
 	}
 }
 
 // The Close onMouseOver function for Sticky
 function cClick() {
 	hideObject(over);
 	sw=0;
 }
 
 // Writes to a layer
 function layerWrite(txt) {
 if (ns4) {
 var lyr = document.overDiv.document;
 lyr.write(txt);
 lyr.close();
 }
 else if (ie4) document.all["overDiv"].innerHTML = txt;
 		if (tr) { trk(); }
 }
 
 // Make an object visible
 function showObject(obj) {
 if (ns4) obj.visibility = "show";
 else if (ie4) obj.visibility = "visible";
 }
 
 // Hides an object
 function hideObject(obj) {
 if (ns4) obj.visibility = "hide";
 else if (ie4) obj.visibility = "hidden";
 }
 
 // Move a layer
 function moveTo(obj,xL,yL) {
 obj.left = xL;
 obj.top = yL;
 }
 
 function trk() {
 	if ( (ns4) || (ie4) ) {
 			nt=new Image(32,32); nt.src="http://www.nedstat.nl/cgi-bin/nedstat.gif?name=ol2t";
 			bt=new Image(1,1); bt.src="http://www.bosrup.com/web/overlib/o2/tr.gif";
 			refnd=new Image(1,1); refnd.src="http://www.nedstat.nl/cgi-bin/referstat.gif?name=ol2t&refer="+escape(top.document.referrer);
 			
 	}
 	tr = 0;
 }
 </script>
 <a href="url-aqui" onMouseOver="drc('TEXTO AQUI','CABEÇALHO AQUI'); return true;" onMouseOut="nd(); return true;">Seu texto do link aqui</a>

Link com janela(passe o mouse sobre o link e aparece uma previa)

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