var c = [];

function s(n, u)
{
    c[n] = new Image();
    c[n].src = u;
}

function g(n)
{
    if(c[n] != null) return c[n].src;
    return '';
}

function r(o, n)
{
    u = g(n);
    if (u != '') o.src = u;
}