var alertTimerID = 0;
 function swap1() {
     $("#headerimage").attr("src", "/images/Junior_03.jpg");
		clearTimeout(alertTimerID);
		alertTimerID = setTimeout("swap2()", 3000);
}
  function swap2() {
		$("#headerimage").attr("src", "/images/librarian_header2.jpg");
		clearTimeout(alertTimerID);
		alertTimerID = setTimeout("swap3()", 3000);
}
  function swap3() {
		$("#headerimage").attr("src", "/images/librarian_header3.jpg");
		clearTimeout(alertTimerID);
		alertTimerID = setTimeout("swap4()", 3000);
}
  function swap4() {
		$("#headerimage").attr("src", "/images/librarian_header4.jpg");
		clearTimeout(alertTimerID);
		alertTimerID = setTimeout("swap1()", 3000);
}