Small pop ups asking for page reload

On my IMac i5 I recently started getting small pop up adds when I am on websites when trying to click next page or typing asking to reload page or back. Once this bypasses nothing will load and I am unable to click on the tool bar. When I try to use the keyboard it just makes a beeping/error sound. This is with a wireless keyboard and Magic Mouse and a hard wired keyboard and mouse. Anyone have a fix before I try a reset to factory setting?