function getImages() {
    if (isIMG) {
      menu1on = new Image(); 
      menu1off = new Image();  
      menu1on.src = "images/menu1alt.gif";
      menu1off.src = "images/menu1.gif";
      menu2on = new Image(); 
      menu2off = new Image();  
      menu2on.src = "images/menu2alt.gif";
      menu2off.src = "images/menu2.gif";
      menu3on = new Image(); 
      menu3off = new Image();  
      menu3on.src = "images/menu3alt.gif";
      menu3off.src = "images/menu3.gif";
      menu4on = new Image(); 
      menu4off = new Image();  
      menu4on.src = "images/menu4alt.gif";
      menu4off.src = "images/menu4.gif";
      menu5on = new Image(); 
      menu5off = new Image();  
      menu5on.src = "images/menu5alt.gif";
      menu5off.src = "images/menu5.gif";
    }
}

var isIMG = document.images;
getImages();

function img_act(imgName) {
    if (isIMG) {
        imgOn = eval(imgName + "on.src");
        document [imgName].src = imgOn;
    }
}



function img_inact(imgName) {
    if (isIMG) {
        imgOff = eval(imgName + "off.src");
        document [imgName].src = imgOff;
    }
}