elseif condition not work in PHP

elseif condition not work in PHP......
any one can solve this problem......

if(file_exists(SS_ROOT.'/thumbs/'.$folder['fid'].'.png'))
{
echo '<img src="'.$ss->settings['url'].'/thumbs/'.$file['fid'].'.png" />';
}
elseif(file_exists(SS_ROOT.'/thumbs/'.$folder['fid'].'.png'))
{
echo '<img src="'.$`enter code here`ss->settings['url'].'/thumbs/'.$folder['fid'].'.png" />';
}
else
{
echo '<img src="'.$ss->settings['url'].'/art.jpg" />';
}


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