Prueba con esto:
<!-- TWO STEPS TO INSTALL AUTO-RESIZABLE-POP-UP:
1. Copy the coding into the HEAD of your HTML document
2. Add the last code into the BODY of your HTML document -->
<!-- STEP ONE: Paste this code into the HEAD of your HTML document -->
<HEAD>
<SCRIPT LANGUAGE="JavaScript">
<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->
<!-- Begin
function CaricaFoto(img){
foto1= new Image();
foto1.src=(img);
Controlla(img);
}
function Controlla(img){
if((foto1.width!=0)&&(foto1.height!=0)){
viewFoto(img);
}
else{
funzione="Controlla('"+img+"')" ;;
intervallo=setTimeout(funzione,20);
}
}
function viewFoto(img){
largh=foto1.width+20;
altez=foto1.height+20;
stringa="width="+largh+",height=&qu ot;+altez;
finestra=window.open(img,"",stringa);
}
// End -->
</script>
</HEAD>
<!-- STEP TWO: Copy this code into the BODY of your HTML document -->
<BODY>
<div align="center">
<TABLE BORDER="1" cellspacing=3>
<TR>
<TD align=left>
<A HREF="javascript
:CaricaFoto('/img/auto-resizable-pop-up/lg-1.gif')" BORDER="0">
<IMG SRC="/img/auto-resizable-pop-up/1.gif" BORDER="0"></A>
</TD>
<TD align=center>
<A HREF="javascript
:CaricaFoto('/img/auto-resizable-pop-up/lg-2.gif')" BORDER="0">
<IMG SRC="/img/auto-resizable-pop-up/2.gif" BORDER="0"></A>
</TD>
<TD align=right>
<A HREF="javascript
:CaricaFoto('/img/auto-resizable-pop-up/lg-4.gif')" BORDER="0">
<IMG SRC="/img/auto-resizable-pop-up/4.gif" BORDER="0"></A>
</TD>
</TR><TR>
<TD colspan=3>
<DIV ALIGN="CENTER">Click para ver la imagen al tamaño real</DIV>
</TD>
</TR>
</TABLE>
</div>
<CENTER>
<IMG SRC="http://www.galeon.com/chileanskies/bannerdm.gif"></CENTER>