function valida(form){
	if(form.msg.value==""){
		window.alert("Por favor preencha o campo com uma frase válida.");
		form.nome.focus();
		return false;
	}else{
		return true;
	}
}
function MM_openBrWindow(theURL,winName,features) { //v2.0
  window.open(theURL,winName,features);
}
function CompartilheTwitter(url,msg){

	texto = msg.substr(0, (137));
	
	if(msg.length >140){
		texto = texto+'...';
	}

	window.open("http://twitter.com/intent/tweet?source=webclient&text="+encodeURIComponent(msg)+" "+encodeURIComponent(url),"sharer","toolbar=0,status=0,width=626,height=436");

}
function CompartilheFacebook(url,msg){
	window.open("http://www.facebook.com/sharer.php?u="+encodeURIComponent(url)+"&t="+encodeURIComponent(msg),"sharer","toolbar=0,status=0,width=626,height=436");
}
function CompartilheOrkut(url,msg){
	window.open("http://promote.orkut.com/preview?nt=orkut.com&du="+encodeURIComponent(url)+"&ctx=share&tt="+encodeURIComponent(msg),"sharer","toolbar=0,status=0,width=626,height=436");
}