if (document.images) {
 img1_on =new Image();  img1_on.src ="./anthology2.png";
 img1_off=new Image();  img1_off.src="./anthology1.png";
 img2_on =new Image();  img2_on.src ="./community2.png";
 img2_off=new Image();  img2_off.src="./community1.png";
 img3_on =new Image();  img3_on.src ="./network2.png";
 img3_off=new Image();  img3_off.src="./network1.png";
 img4_on =new Image();  img4_on.src ="./services2.png";
 img4_off=new Image();  img4_off.src="./services1.png";
}
 function bright(x) {
 if (document.images) 
  eval('document.img'+x+'.src=img'+x+'_on.src');
}
function light(x) {
 if (document.images) 
  eval('document.img'+x+'.src=img'+x+'_off.src');
}