jQuery.fn.toggleText = function(a,b) {
return   this.html(this.html().replace(new RegExp("("+a+"|"+b+")"),function(x){return(x==a)?b:a;}));
}

$(document).ready(function(){
$('.tgl').before('<SPAN>Caso seja <strong>Professor</strong>, clique aqui</SPAN>');
$('.tgl').css('display', 'none')

$('.tgl2').before('<SPAN>Caso seja <strong>Aluno</strong>, clique aqui</SPAN>');
$('.tgl2').css('display', 'none')

$('.tgl3').before('<SPAN>Caso seja <strong>Profissional</strong> da Área, clique aqui</SPAN>');
$('.tgl3').css('display', 'none')

$('span', '#box-toggle').click(function() {
$(this).next().slideToggle('slow')
.siblings('.tgl:visible, .tgl2:visible, .tgl3:visible').slideToggle('fast');
// aqui começa o funcionamento do plugin
$(this).toggleText('aqui','para esconder')
.siblings('span').next('.tgl:visible, .tgl2:visible, .tgl3:visible').prev()
.toggleText('aqui','para esconder')
});
})