Código:
<html> <head> <script language="javascript"> //fades layer in ie5 = (document.all && document.getElementById); ns6 = (!document.all && document.getElementById); opac = 0; function fadein() { if(opac!= 100){ opac+=1; if(ie5) document.getElementById('nameoflayer').filters.alpha.opacity = opac; if(ns6) document.getElementById('nameoflayer').style.MozOpacity = opac/100; setTimeout('fadein()', 2); } } function fadeOut() { if(opac!= 0){ opac+=1; if(ie5) document.getElementById('nameoflayer').filters.alpha.opacity = opac; if(ns6) document.getElementById('nameoflayer').style.MozOpacity = opac/0; setTimeout('fadeOut()', 2); } } function MM_callJS(jsStr) { //v2.0 return eval(jsStr) } </script> </head> <body> <div onClick="MM_callJS('fadein()')">fadein</div> <div onClick="MM_callJS('fadeOut()')">fadeout</div> <div id="nameoflayer" style="position:absolute; left:100px; top:150px; width:100px; height:100px; clip:rect(0,100,100,0); filter: alpha(opacity=0); -moz-opacity:0; background-color:red; z-index:1"> </div> </body> </html>