All New V2 version of Visualforce Autocomplete Component

• The component now uses Select2 instead of Jquery Autocomplete
• Much more faster than earlier version and can handle large dataset Complete new UI
• The component no more depends on the Jquery from the package and can use jquery from Visualforce page(if already referred in page).
• Configurable : The search field can be configured to search fields other than "Name" field. Even the value that is returned to controller can be configured return fields other than record Id.

<c:AutoCompleteV2 allowClear="true" importJquery="true" labelField="Name" SObject="Account" valueField="Id" targetField="{!targetField}" style="width:200px"/>  

• labelField : The field which is displayed in the component and against which matching is done with the entered text. In above code snippet Name is displayed in the autocomplete component.
• valueField : The field value which is passed back to targetfield when a record is selected.
• targetField : The field from controller where the selected values is set.
• SObject : The sobject Api Name against which matching/query is done.
• importJquery : Assign false if you dont want to jquery files from package.
• syncManualEntry : Allow manual entry of data from autocomplete component. So if a matching value is not found for the entered query string, on page submit the same value will be sibmitted to targefield
• allowClear : Set true to give user a option to clear existing value. If this value is set true user will see a small cross Icon to clear the existing value from the field

In addition to this a Visualforce Page "AutocompleteV2Demo" is included in package. This page searches through different accounts that are available in the Org. Have a look at the same for syntax and implementation

http://blogforce9dev-developer-edition.ap1.force.com/AutocompleteV2Demo

https://login.salesforce.com/packaging/installPackage.apexp?p0=04t90000000MeZh