function rev21(){
vr = open('revista_imagem/numero20', 'principal', 'status=no, location=no, toolbar=no, menubar=no, location=no, fullscreen=1, scrolling=auto')
}
function rev22(){
vr = open('revista_imagem/numero22', 'principal', 'status=no, location=no, toolbar=no, menubar=no, location=no, fullscreen=1, scrolling=auto')
}
function rev23(){
vr = open('http://www.institutobrasil.com/revista_imagem/numero23', 'principal', 'status=no, location=no, toolbar=no, menubar=no, location=no, fullscreen=1, scrolling=auto')
}