You can use the 
HTML Element Properties dialog to edit a Control's ID and Class Locators.
Each HTML element can only have one Id, but can have multiple Class Locators. These Locators directly map to HTML id and class attributes.
Id Locators must be unique across a Page, therefore Controls inside a 
Repeater Row Control cannot be assigned an Id.
jQuery Event Handlers require a Locator to bind the handler to the event.