if ( document.images ) {
    mnu_pf_1_on = new Image(); mnu_pf_1_on.src="/common/images/mnu_pf_1_on.gif";
    mnu_pf_1_off = new Image(); mnu_pf_1_off.src="/common/images/mnu_pf_1_off.gif";
    mnu_pf_2_on = new Image(); mnu_pf_2_on.src="/common/images/mnu_pf_2_on.gif";
    mnu_pf_2_off = new Image(); mnu_pf_2_off.src="/common/images/mnu_pf_2_off.gif";
    mnu_pf_3_on = new Image(); mnu_pf_3_on.src="/common/images/mnu_pf_3_on.gif";
    mnu_pf_3_off = new Image(); mnu_pf_3_off.src="/common/images/mnu_pf_3_off.gif";
}