E 18 problem. The lens on my Canon digital camera will not close... i am unable to take a pciture

Question

The lens on my Canon digital camera will not close... i am unable to take a pciture and do not know the reason for this....when the camera is put on i am able to see my old pictures but when i click to take a new picture the screen is blank..i dont know what to do...please help...i have the canon power shot sd 500 camera and the problem that appears is the E18...... please help meCanon Power Shot A610 The lens stays shut. The code E18 is shown in the lefthand bottom corner. The pictures already taken are shown but I cannot take any more. I've tried banging in the palm of my hand, have changed the batteries.