try{if(target == null){target="_blank";}}catch(exception){target="_blank";}
try{if(altura == null){altura="31";}}catch(exception){altura="31";}
try{if(largura == null){largura="88";}}catch(exception){largura="88";}
try{if(classe_css == null){classe_css="brtones";}}catch(exception){classe_css="brtones";}

document.write("<a href='http://www.brtones.com' target=" + target + "><img class='" + classe_css + "' src='http://www.brtones.com/img/externo/button" + largura + "x" + altura + ".gif' alt='brTones!.com - Toques de celular gratuitos!' width='" + largura + "' height='" + altura + "' border='0' /></a>")