imghome150on = new Image();
imghome150on.src = "images/home_on.gif";
imghome150off = new Image();
imghome150off.src = "images/150home_off.gif";

imgcatalogs150on = new Image();
imgcatalogs150on.src = "images/catalogs_on.gif";
imgcatalogs150off = new Image();
imgcatalogs150off.src = "images/150catalogs_off.gif";

imglinks150on = new Image();
imglinks150on.src = "images/links_on.gif";
imglinks150off = new Image();
imglinks150off.src = "images/150links_off.gif";

imgfree150on = new Image();
imgfree150on.src = "images/free_on.gif";
imgfree150off = new Image();
imgfree150off.src = "images/150free_off.gif";

imgabout150on = new Image();
imgabout150on.src = "images/about_on.gif";
imgabout150off = new Image();
imgabout150off.src = "images/150about_off.gif";

imgcontact150on = new Image();
imgcontact150on.src = "images/contact_on.gif";
imgcontact150off = new Image();
imgcontact150off.src = "images/150contact_off.gif";

// links image functions
function imgAct(imgName) {
    document[imgName].src = eval(imgName + "on.src");
}

function imgInact(imgName) {
    document[imgName].src = eval(imgName + "off.src");
}