AJAX based field in document library default new form

I have a field in my document library which is reading data from another field in the same library.

For this to achieve I am using Lookup field which is working fine. But I want to change it so instead of a drop down where the user selects value from lookup, I want to give a textbox and as user starts typing, it reads data from lookup field and start displaying results which user can choose.

I am talking about the same "instant search" feature which is commonly around or another example is User field in SharePoint form, which when you start typing user name, shows you name from the AD.

So is it possible to do the same in EditForm.aspx?