If string is found in range Yes else No

I think I am almost there, I got this formule:

=IF(ISNUMBER(MATCH("READONLY";D17:P17;0));"FOUND";"NOT FOUND")

I would like to search record based for the text READONLY. So if READONLY is found then FOUND else NOT FOUND. Please note that the cells that contain READONLY also contain other text, for example: 'fsdfsdfssfs READONLY'

Thanks in advance