Dear Mr/Mrs
 i bind full name of company in RadDropdownList from database . in auto complete property i have to enter part of first name to get some suggests names. what i want is enter part of S.name Or last name to get some suggests names. for example:
RadDropdownList items are:
-"Rami Ahmed Ziad"
-"Anas Rafik Ibrahim"
-"Ahmed Hany Ali"
-"Reham Morsy Ali"

when i write "r" all items starting with 'r' listed "Rami Ahamed Ziad" and "Reham Morsy Ali" .but what i want is "Rami Ahmed Ziad"
,"Anas Rafik Ibrahim" and "Reham Morsy Ali" i hope it si clear now.
Thank you
Rami

Hello Rami,

Thank you for writing.

Your question has already been answered in the support thread you have opened. 

We kindly ask you to use just one support channel to contact us. Posting the same questions numerous times slows down our response time because we will need to review and address two or more tickets instead of one. Moreover threads are handled according to license and time of posting, so if it is an urgent problem, we suggest you use a support ticket, which would be handled before a forum thread.

I am copying the answer from the support ticket here, so the community can benefit from it:
You should set AutoCompleteSuggest helper SuggestMode property to Contains:

Thank you for your understanding.

Regards, Dimitar
Telerik