para colocar em varios tamanhos eh so vc adicionar um numero na funcao poptastic0, poptastic1, poptastic2, igual a os 2 exemplos abaixo:

 
<script language="Java Script" type="text/JavaScript"> 
<!-- 
function poptastic0(url) 
{ 
newwindow=window.open(url,'name','height=400,width=400,left=0,top=0'); 
if (window.focus){newwindow.focus()} 
} 
//--> 
</script> 
<a href="javascript:poptastic0('teste.php')">Clique aqui</a>



<script language="Java Script" type="text/JavaScript"> 
<!-- 
function poptastic1(url) 
{ 
newwindow=window.open(url,'name','height=200,width=200,left=0,top=0'); 
if (window.focus){newwindow.focus()} 
} 
//--> 
</script> 
<a href="javascript:poptastic1('teste.php')">Clique aqui</a>