add_theme_support( 'post-thumbnails');
set_post_thumbnail_size( 150, 150, true );
add_image_size( 'single-post-thumbnail', 150, 150);
add_theme_support( 'post-thumbnails');
set_post_thumbnail_size( 150, 150, true );
add_image_size( 'single-post-thumbnail', 150, 150);