See input (type="file").

This is single character key that either gives focus to an fileUpload element (in some browsers) or activates a form control or link action.

Removes focus from the current fileUpload object, at which time the fileUpload object's onblur event fires.

Specifies whether the fileUpload element is available for user interaction. When set to true, the element cannot receive focus or be modified by the u

Gives focus from the current fileUpload object, at which time the fileUpload object's onfocus event fires.

This is a number that indicates the sequence of this fileUpload element within the tabbing order of all focusable elements in the document.