Timeline Beyond 3D - Keyframes

[YousriLaseronics]

Hi, i have done an Animation in Byond 3d in 100 Frames. Now i want to extend the animation and move the Keyframes that have been placed at the 100th frame to 150th frame. I extended the frame numbers to 200 and tried to move the keyframes. But couldnt move the Keyframes. Thank you for your help in advance.
Yousri