Corta link! mudar link!

<html>

<meta charset="utf-8">

<h1>Criar janela window popT</h1>

<button onclick="jsPopunder()">Abrir</button>

<script>

function jsPopunder() {

    window.open("https://messiasopoeta.blogspot.com/","PAGINA1",'scrollbars=no,width=235,height=155,left=100,top=200,screenX=100,screenY=200');

    window.open("https://messiasopoeta.blogspot.com/","PAGINA2",'scrollbars=no,width=235,height=155,left=1000,top=200,screenX=1000,screenY=200');

        window.open("https://messiasopoeta.blogspot.com/","PAGINA3",'scrollbars=no,width=235,height=155,left=100,top=200,screenX=100,screenY=200');

            window.open("https://messiasopoeta.blogspot.com/","PAGINA4",'scrollbars=no,width=235,height=155,left=100,top=200,screenX=100,screenY=200');

    //window.open("http://www.dominio.com/","PAGINA3",........

    //window.open("http://www.dominio.com/","PAGINA4",........



}

</script>

</html>