<meta charset="UTF-8">
<script>
function pulaLinha() {
document.write("<br>");
document.write("<br>");
}
function mostra(frase) {
document.write(frase);
pulaLinha();
}
var numInicial = 20;
while (numInicial >=0){
mostra (numInicial)
numInicial =numInicial-1;
}
mostra("FIM");
</script>