Autocomplete Demonstration Issue- Not replacing full text

Hi

I have used Autocomplete extender to search records in my ecommerce website.

When I select a record from recommended list of results, it does not replaces complete text in search bar. It only replaces the last word.

For Example : if i type Dell Vostro and i choose a result from recommended list of results (Dell Vostro 520), it replaces only "Vostro" and gives Dell Dell Vostro 520.

How to replace full text. I am using the same code as provided in the sample toolkit.