How to remove focus from input field in jQuery?

Use .blur().

The blur event is sent to an element when it loses focus. Originally, this event was only applicable to form elements, such as <input>. In recent browsers, the domain of the event has been extended to include all element types. An element can lose focus via keyboard commands, such as the Tab key, or by mouse clicks elsewhere on the page.

$("#myInputID").blur(); 

check up blur():

$('#textarea').blur()

source: http://api.jquery.com/blur/