Page up tuşunun görevi aşağıdakilerden hangisidir?

{"commentics_url":"\/\/www.sorubak.com\/yorum\/","page_id":2465662,"enabled_country":false,"country_id":158,"enabled_state":false,"state_id":0,"enabled_upload":false,"maximum_upload_amount":3,"maximum_upload_size":5,"maximum_upload_total":5,"securimage":false,"securimage_url":"\/\/www.sorubak.com\/yorum\/3rdparty\/securimage\/securimage_show.php?namespace=cmtx_2465662","cmtx_wait_for_comment":"cmtx_wait_for_comment","lang_error_file_num":"A maximum of %d files are allowed to be uploaded","lang_error_file_size":"Please upload files no bigger than %.1f MB in size","lang_error_file_total":"The total size of all files must be less than %.1f MB","lang_error_file_type":"Only image file types are allowed to be uploaded","lang_text_loading":"Y\u00fckleniyor ..","lang_placeholder_country":"Country","lang_placeholder_state":"State","lang_text_country_first":"L\u00fctfen \u00f6nce bir \u00fclke se\u00e7in","lang_button_submit":"G\u00f6nder","lang_button_preview":"\u00d6nizle","lang_button_remove":"Sil","lang_button_processing":"PL\u00fctfen Bekleyiniz..."}