<script>
function submitForm(row_id, user_id)
{
    document.getElementById('row_id').value = row_id;
    document.getElementById('user_id').value = user_id;
    document.getElementById('detail_form').submit();
}
</script>

<form action="detail.php" method="post" id="detail_form">
<input type="hidden" name="id" id="row_id">
<input type="hidden" name="user_id" id="user_id">
</form>

<?php
for(....)
{
    ?>
    <span style="cursor: pointer;" onclick="submitForm(<?php echo $row_id; ?>, <?php echo $user_id; ?>);">READ MORE</span>
    <?php
}