function show(a) {
    var el = document.getElementById('el_' + a);
    document.getElementById('el_1').style.display='none';
    document.getElementById('el_2').style.display='none';
    document.getElementById('el_3').style.display='none';
    el.style.display='block';
}

function show1(a) {
    var mv = document.getElementById('mv_' + a);
    document.getElementById('mv_1').style.display='none';
    document.getElementById('mv_2').style.display='none';
    mv.style.display='block';
}

function show2(a) {
    var pstr = document.getElementById('pstr_' + a);
    document.getElementById('pstr_1').style.display='none';
    document.getElementById('pstr_2').style.display='none';
    document.getElementById('pstr_3').style.display='none';
    document.getElementById('pstr_4').style.display='none';
    document.getElementById('pstr_5').style.display='none';
    pstr.style.display='block';
}