function change11() {
     var img1 = document.getElementById("img11").src = "images/2009_1_hover.gif";
     var img2 = document.getElementById("img21").src = "images/2009_2_link.gif";
     var img3 = document.getElementById("img31").src = "images/2009_3_link.gif";
     var img4 = document.getElementById("img41").src = "images/2009_4_link.gif";
     var img5 = document.getElementById("img51").src = "images/2009_5_link.gif";

 }

 function change21() {
     var img1 = document.getElementById("img11").src = "images/2009_1_link.gif";
     var img2 = document.getElementById("img21").src = "images/2009_2_hover.gif";
     var img3 = document.getElementById("img31").src = "images/2009_3_link.gif";
     var img4 = document.getElementById("img41").src = "images/2009_4_link.gif";
     var img5 = document.getElementById("img51").src = "images/2009_5_link.gif";

 }
 function change31() {
     var img1 = document.getElementById("img11").src = "images/2009_1_link.gif";
     var img2 = document.getElementById("img21").src = "images/2009_2_link.gif";
     var img3 = document.getElementById("img31").src = "images/2009_3_hover.gif";
     var img4 = document.getElementById("img41").src = "images/2009_4_link.gif";
     var img5 = document.getElementById("img51").src = "images/2009_5_link.gif";

 }
 function change41() {
     var img1 = document.getElementById("img11").src = "images/2009_1_link.gif";
     var img2 = document.getElementById("img21").src = "images/2009_2_link.gif";
     var img3 = document.getElementById("img31").src = "images/2009_3_link.gif";
     var img4 = document.getElementById("img41").src = "images/2009_4_hover.gif";
     var img5 = document.getElementById("img51").src = "images/2009_5_link.gif";

 }
 function change51() {
     var img1 = document.getElementById("img11").src = "images/2009_1_link.gif";
     var img2 = document.getElementById("img21").src = "images/2009_2_link.gif";
     var img3 = document.getElementById("img31").src = "images/2009_3_link.gif";
     var img4 = document.getElementById("img41").src = "images/2009_4_link.gif";
     var img5 = document.getElementById("img51").src = "images/2009_5_hover.gif";

 }