1.
if(1 == @$manta_option['iso_format_recent_works']){
$theme_img = 'recent_works_thumbnail';
} else {
$theme_img = 'recent_works_iso_thumbnail';
}
2.
if(isset($manta_option['iso_format_recent_works']) && 1 == $manta_option['iso_format_recent_works']){
$theme_img = 'recent_works_thumbnail';
} else {
$theme_img = 'recent_works_iso_thumbnail';
}
3.
if (!empty($manta_option['iso_format_recent_works']) && $manta_option['iso_format_recent_works'] == 1){
}
else{
}