Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /home/iewfm/public_html/research/include/dbconnection.php on line 9

php error happened

Technical information
Error type2
Error descriptionCannot modify header information - headers already sent by (output started at /home/iewfm/public_html/research/include/dbconnection.php:9)
URLiewfm.starhostbd.com/research/research_list.php?
Error file/home/iewfm/public_html/research/include/commonfunctions.php
Error line3909
SQL query

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