var current = 0;

// Create image objects, preload all active and inactive images.
img1off=new Image();
img1off.src="images/ipd_main_nav_home_off.gif";
img2off=new Image();
img2off.src="images/ipd_main_nav_signup_off.gif";
img3off=new Image();
img3off.src="images/ipd_main_nav_abtconn_off.gif";
img4off=new Image();
img4off.src="images/ipd_main_nav_support_off.gif";
img5off=new Image();
img5off.src="images/ipd_main_nav_mgacct_off.gif";

img1on=new Image();
img1on.src="images/ipd_main_nav_home_on.gif";
img2on=new Image();
img2on.src="images/ipd_main_nav_signup_on.gif";
img3on=new Image();
img3on.src="images/ipd_main_nav_abtconn_on.gif";
img4on=new Image();
img4on.src="images/ipd_main_nav_support_on.gif";
img5on=new Image();
img5on.src="images/ipd_main_nav_mgacct_on.gif";

// Function to "activate" images.
function imgAct(imgName)
{
    document[imgName].src=eval(imgName+"on.src");
}

// Function to "deactivate" images.
function imgInact(imgName)
{
    document[imgName].src=eval(imgName+"off.src");
}

function setmenu(idx)
{
    current = idx;
    imgAct('img'+idx);
}

function updatemenu(idx, action)
{
    if (action == 'on')
    {
        imgAct('img'+idx);
    }
    else if (current != idx)
    {
        imgInact('img'+idx);
    }
}