mukandknit 0 Newbie Poster

Hi,
I have been trying for having pop up menu inside textarea while typing on it. while typing, it takes the text from the textarea and should display 4-5 options in textarea at the point of typing and if we select any option , it replaces the word being typed like in google indic transliteration. I have done all part but just menu part is left. I am searching on net from 2 weeks but found nothing useful . I am using javascript only. I m new to web programming . Can anyone help me out of this. how to do this ???