If you don't want to submit a form, the only two other ways of accomplishing this are to click a link with the data as query parameters in the url, or use AJAX to send the data to the server in the background.
update:
Javascript, as usual. You'd put a link or button somewhere on the page with "Send to Server" or whatever for the text. The script would pull your information from the input fields, and then send it on to the server via an AJAX call. Something along these lines (note that I'm using Mootools for all this, as it makes life much easier than having to do the remote calls yourself):
function clickHandler() {
var img1 = $$("input[name='img1']")[0].value;
var r = new Request.JSON({
'url: 'http://yourserver.example.com/script.php',
'method': 'post',
'onComplete': function(success) { alert('AJAX call status: ' + (success ? 'succeeded': 'failed!'); },
'onFailure': function() { alert('Could not contact server'); },
'data': 'img1=' + img1
}).send();
}
and on the server you'd have something like:
<?php
$img1 = mysql_real_escape_string($_POST['img1']);
$idx=1;
$sql="INSERT INTO games SET img1='$img1' WHERE id=$idx";
$result=mysql_query($sql);
echo (($result !== FALSE) ? 1 : 0);
You'd probably want something more complicated than this, but this is the basis of an AJAX application. Some client-side javascript that makes requests, and a script on the server that handles them and returns any data/errors as needed.