FLASH PLARER WILL NOT INSTALL

I have a OSX I mac. I have been getting the message that I need to install a new version if FLASH PLAYER. I install as per the instructions, use it to look at a video on a search engine, and then next time I need to use it, it tells me again I need to install a new version if FLASH PLAYER. I have tried to install it a number of times with no continued success. What do I do?