All form fields (except for hidden fields) contain common properties, methods, and events:
disabled propertyindicate whether the control is disabled as well as to actually disable the control (a disabled control doesn't allow any user input, but gives no visual indication that the control is disabled).
form propertya pointer back to the form of which the field is a part.
blur() methodcauses the form field to lose focus (by shifting the focus elsewhere).
focus() methodcauses the form field to gain focus (the control is selected for keyboard interaction).
blur eventoccurs when the field loses focus; the onblur event handler is then executed.
focus eventoccurs when the field gains focus; the onfocus event handler is then executed.