ok, Your FTP program may support chmod. Look at the pic below. To chmod to 777, you want to check all the boxes. chmoding to 777 is very odd to suggest because it basically means you allow anyone to read and write to that directory. Are you able to create a directory outside the public html directory?

EDIT: I am typing too fast. by public html, I mean are you able to create a directory outside 'htdocs'