if (document.images) {
img1on = new Image();   img1on.src = "images/but1a.gif";
img2on = new Image();   img2on.src = "images/but2a.gif";
img3on = new Image();   img3on.src = "images/but3a.gif";
img4on = new Image();   img4on.src = "images/but4a.gif";
img5on = new Image();   img5on.src = "images/but5a.gif";
img6on = new Image();   img6on.src = "images/but6a.gif";
img7on = new Image();   img7on.src = "images/but7a.gif";
img8on = new Image();   img8on.src = "images/but8a.gif"; 
img9on = new Image();   img9on.src = "images/but9a.gif"; 
img24on = new Image();   img24on.src = "images/but10a.gif"; 
img23on = new Image();   img23on.src = "images/but51a.gif"; 
img12on = new Image();   img12on.src = "images/but12a.gif"; 

       			
img1off = new Image();  img1off.src = "images/but1.gif";
img2off = new Image();  img2off.src = "images/but2.gif";
img3off = new Image();  img3off.src = "images/but3.gif";
img4off = new Image();  img4off.src = "images/but4.gif";
img5off = new Image();  img5off.src = "images/but5.gif";
img6off = new Image();  img6off.src = "images/but6.gif";
img7off = new Image();  img7off.src = "images/but7.gif";
img8off = new Image();  img8off.src = "images/but8.gif";
img9off = new Image();  img9off.src = "images/but9.gif";
img24off = new Image();  img24off.src = "images/but10.gif";
img23off = new Image();  img23off.src = "images/but51.gif";
img12off = new Image();  img12off.src = "images/but12.gif";
}function imgOn(imgName) {if (document.images) {document[imgName].src = eval(imgName + "on.src");}}function imgOff(imgName) {if (document.images) {document[imgName].src = eval(imgName + "off.src");}}