International Standard Version because everyone who keeps asking will receive, and the person who keeps searching will find, and the person who keeps knocking will have the door opened.
American Standard Version For every one that asketh receiveth; and he that seeketh findeth; and to him that knocketh it shall be opened.
Young's Literal Translation for every one who is asking doth receive; and he who is seeking doth find; and to him who is knocking it shall be opened.