imag = new Array();

imag[0] = "images/menu_services_on.gif";
imag[1] = "images/menu_services_off.gif";
imag[2] = "images/menu_investment_on.gif";
imag[3] = "images/menu_investment_off.gif";
imag[4] = "images/menu_AboutUs_on.gif";
imag[5] = "images/menu_AboutUs_off.gif";
imag[6] = "images/menu_contacts_on.gif";
imag[7] = "images/menu_contacts_off.gif";

function swtch(num,imgname){
     imgname.src = im[num].src
}

im = new Array()

for (var i = 0; i < imag.length; i++){
       im[i] = new Image()
       im[i].src = imag[i]
}