How to make custom block , by default left region, this is my snippet

<?php function contactus_block($op='list', $delta=0) { // listing of blocks, such as on the admin/block page if ($op == "list") { $blocks[0] = array('info'=> t('Contact Us Block'),'weight' => 0, 'enabled' => 1, 'region' => 'left'); return $blocks; } else if ($op == 'view') { $ganesh = "weclome"; $block['content'] = $ganesh; return $block; } }

function contactus_perm() {

return array('access contactus', 'create contactus', 'administer contactus');

}