var cuantosbanners = 12; 
var ahora = new Date() 
var segundos = ahora.getSeconds() 
var banner = segundos % cuantosbanners; 
banner +=1; 

if (banner==1) { 
url=" http://www.tucasaweb.com/cgi-bin/interesado/interesado.asp?idiomapagina=ESP&interesado=SI&titulo=SERVICIOS%20INFORMÁTICOS&comentarios=Explíquenos%20en%20qué%20podemos%20ayudarle. "; 
alt=" Solicita información "; 
imagen=" http://www.tucasaweb.com/banners/asie1.gif "; 
width=" 140 "; 
height=" 80 "; 
} 
if (banner==2)  { 
url=" http://www.tucasaweb.com/gestinmobiliaria/ "; 
alt=" Visítanos ... "; 
imagen=" http://www.tucasaweb.com/banners/asie2.gif "; 
width=" 140 "; 
height=" 80 "; 
} 
if (banner==3) { 
url=" http://www.tucasaweb.com/gestvehiculo/ "; 
alt=" Visítanos ... "; 
imagen=" http://www.tucasaweb.com/banners/asie3.gif "; 
width=" 140 "; 
height=" 80 "; 
} 
if (banner==4) { 
url=" http://www.tucasaweb.com/gestartista/ "; 
alt=" Visítanos ... "; 
imagen=" http://www.tucasaweb.com/banners/asie4.gif "; 
width=" 140 "; 
height=" 80 "; 
} 
if (banner==5) { 
url=" http://www.tucasaweb.com/cgi-bin/interesado/interesado.asp?idiomapagina=ESP&interesado=SI&titulo=CERÁMICA%20COCKTAIL&comentarios=Explíquenos%20en%20qué%20podemos%20ayudarle. "; 
alt=" Solicita información "; 
imagen=" http://www.tucasaweb.com/banners/ceramicacocktail1.gif "; 
width=" 140 "; 
height=" 80 "; 
} 
if (banner==6) { 
url=" http://www.tucasaweb.com/cgi-bin/interesado/interesado.asp?idiomapagina=ESP&interesado=SI&titulo=ESCUELA%20TÉCNICA&comentarios=Explíquenos%20en%20qué%20podemos%20ayudarle. "; 
alt=" Solicita información "; 
imagen=" http://www.tucasaweb.com/banners/escuelatecnica1.gif "; 
width=" 140 "; 
height=" 80 "; 
} 
if (banner==7) { 
url=" http://www.tecnorotul.com/cgi-bin/inicio.asp?codarticulo=1042 "; 
alt=" Visítanos ... "; 
imagen=" http://www.tucasaweb.com/banners/placasgrabadas2.gif "; 
width=" 140 "; 
height=" 80 "; 
} 
if (banner==8) { 
url=" http://www.tucasaweb.com/cgi-bin/interesado/interesado.asp?idiomapagina=ESP&interesado=SI&titulo=SERVIDECOR&comentarios=Explíquenos%20en%20qué%20podemos%20ayudarle. "; 
alt=" Solicita información "; 
imagen=" http://www.tucasaweb.com/banners/servidecor1.gif "; 
width=" 140 "; 
height=" 80 "; 
} 
if (banner==9) { 
url=" http://www.tucasaweb.com/cgi-bin/interesado/interesado.asp?idiomapagina=ESP&interesado=SI&titulo=SERVIDECOR&comentarios=Explíquenos%20en%20qué%20podemos%20ayudarle. "; 
alt=" Solicita información "; 
imagen=" http://www.tucasaweb.com/banners/servidecor4.gif "; 
width=" 140 "; 
height=" 80 "; 
} 
if (banner==10) { 
url=" http://www.tecnorotul.com/ "; 
alt=" Visítanos ... "; 
imagen=" http://www.tucasaweb.com/banners/tecnorotul1.gif "; 
width=" 140 "; 
height=" 80 "; 
} 
if (banner==11) { 
url=" http://www.tecnorotul.com/ "; 
alt=" Visítanos ... "; 
imagen=" http://www.tucasaweb.com/banners/tecnorotul2.gif "; 
width=" 140 "; 
height=" 80 "; 
} 
if (banner==12) { 
url=" http://www.tecnorotul.com/ "; 
alt=" Visítanos ... "; 
imagen=" http://www.tucasaweb.com/banners/tecnorotul3.gif "; 
width=" 140 "; 
height=" 80 "; 
} 

document.write('<a href="' + url + '" target="_blank">'); 
document.write('<img src="' + imagen + '" width=' + width + ' height=' + height + ' alt="' + alt + '" border=0>'); 
document.write('</a>');