Needs help in Key Frame

Hi: I create 5 key frames and type each character of Hello on each frame. When i run the program it shows first H then H disappear then it shows E then E disappear then it shows L and then L disappear then it shows again L and then at end it shows O.

Can any one please tell me how to i create frames so that nothing will be disappear first it shows H then after 2 seconds it shows E then one one by all the characters of Hello a complete one word will be appear on the screen?

Thanks.