Verbal, вот некая иллюстрация предложенного...
<!DOCTYPE html>
<html>
<head>
<!--
<script src='http://code.jquery.com/jquery-latest.js'></script>
<link rel='stylesheet type=text/css href=tmp.css' />
-->
<style type='text/css'>
</style>
<script type='text/javascript'>
function ok() {
var val=confirm('Send data?');
return val;
};
</script>
</head>
<body>
<form onsubmit='return ok();'>
<input type='text' />
<button>Send</button>
</form>
</body>
</html>