function nav_biaoqian_1(){
nav_biaoqian_1_1.className = "nav_biaoqian_a_1_on";
nav_biaoqian_2_1.className = "nav_biaoqian_a_1_off";
xin_xi_jiao_liu_1.className = "xianshi";
xin_xi_jiao_liu_2.className = "yincang";
}

function nav_biaoqian_2(){
nav_biaoqian_1_1.className = "nav_biaoqian_a_1_off";
nav_biaoqian_2_1.className = "nav_biaoqian_a_1_on";
xin_xi_jiao_liu_1.className = "yincang";
xin_xi_jiao_liu_2.className = "xianshi";
}