Lets modify our SR Flip-flop and provide a clock enable. This means that the output will change only when clock is '1', otherwise all inputs will be ignored. Note that this is leveled enable, i.e the input can change flip-flop's output only while the clock is '1'. While the clock is '0', all the inputs will be ignored.
Small modification done in S-R flip-flop to provide clock enable is shown below...