how to show textbox collection list

Question

H everyone,
I have one textbox(txtNames). I assign some names list to that textbox using AutoCompleteCollectionString.
After assignning values to the textbox once we type any letter on textbox, based on that letter
intellisence will show the related list data.
My requirement is once focus to that textbox i want to show all the list of the names without type any letter on textbox.
Regards,
Jeevan