The focus event is sent to an element when it gains focus. This event is implicitly applicable to a limited set of elements, such as form elements (<input>, <select>, etc.) and links (<a href>). In recent browser versions, the event can be extended to include all element types by explicitly setting the element's tabindex property. An element can gain focus via keyboard commands, such as the Tab key, or by mouse clicks on the element.
To focus on Div element using jQuery its required to DIV element has tabindex property value -1. so set:
<div id="mydiv" tabindex="-1"></div>