//subnavi init:
submenu1_lo = new Image();
submenu1_hi = new Image();
submenu2_lo = new Image();
submenu2_hi = new Image();
submenu3_lo = new Image();
submenu3_hi = new Image();
submenu4_lo = new Image();
submenu4_hi = new Image();
submenu5_lo = new Image();
submenu5_hi = new Image();
submenu6_lo = new Image();
submenu6_hi = new Image();

submenu1_lo.src = "img/navis/sub_technique_intro_lo.gif";
submenu1_hi.src = "img/navis/sub_technique_intro_hi.gif";
submenu2_lo.src = "img/navis/sub_technique_principles_lo.gif";
submenu2_hi.src = "img/navis/sub_technique_principles_hi.gif";
submenu3_lo.src = "img/navis/sub_technique_components_lo.gif";
submenu3_hi.src = "img/navis/sub_technique_components_hi.gif";
submenu4_lo.src = "img/navis/sub_technique_contrastagents_lo.gif";
submenu4_hi.src = "img/navis/sub_technique_contrastagents_hi.gif";
submenu5_lo.src = "img/navis/sub_technique_examination_lo.gif";
submenu5_hi.src = "img/navis/sub_technique_examination_hi.gif";
submenu6_lo.src = "img/navis/sub_technique_normalanatomy_lo.gif";
submenu6_hi.src = "img/navis/sub_technique_normalanatomy_hi.gif";