codice:
<script> 
var img = new Array(); 

img[0] = '[img]2.jpg[/img]';
img[1] = '[img]2.jpg[/img]'; 
img[2] = '[img]2.jpg[/img]'; 
img[3] = '[img]2.jpg[/img]'; 
img[4] = '[img]2.jpg[/img]'; 
img[5] = '[img]2.jpg[/img]'; 
img[6] = '[img]2.jpg[/img]'; 


var img_url = new Array(); 
img_url[0] = "1.jpg"; 
img_url[1] = "2.jpg"; 
img_url[2] = "3.jpg"; 
img_url[3] = "4.jpg"; 
img_url[4] = "logo.jpg"; 
img_url[5] = "pippo.jpg"; 
img_url[6] = "uno.jpg"; 



document.write ("<table border='1'>"); 
for (i=0; i<img_url.length; i++) { 
if (i%4 == 0){ 
document.write ("<tr><td>" + img[i] + "</td>"); 
} 
else if(i%4 == 3){ 
document.write ("<td>" + img[i] + "</td></tr>"); 
} 
else{ 
document.write ("<td>" + img[i] + "</td>"); 
} 
} 
document.write ("</table>"); 
</script>
prova così