function calc_ratio(key) {
    var D  = (document.form1["D"  + key])? document.form1["D"  + key].value : null;
    var DA = (document.form1["DA" + key])? document.form1["DA" + key].value : null;
    var DB = (document.form1["DB" + key])? document.form1["DB" + key].value : null;
    var W  = (document.form1["W"  + key])? document.form1["W"  + key].value : null;
    var L  = (document.form1["L"  + key])? document.form1["L"  + key].value : null;
    var P  = (document.form1["P"  + key])? document.form1["P"  + key].value : null;
    var PA = (document.form1["PA" + key])? document.form1["PA" + key].value : null;
    
    var exp_list = {
        1: '90.6*(parseFloat(D)*parseFloat(D))/(parseFloat(P)*parseFloat(P))',
        2: '157*(parseFloat(D)*parseFloat(D))/(parseFloat(P)*parseFloat(P))',
        3: '78.5*(parseFloat(D)*parseFloat(D))/(parseFloat(P)*parseFloat(PA))',
        4: '100*(parseFloat(DA)*parseFloat(DB))/(parseFloat(P)*parseFloat(PA))',
        5: '100*2*(parseFloat(DA)*parseFloat(DB))/(parseFloat(P)*parseFloat(PA))',
        6: '100*((2*parseFloat(W)*parseFloat(L)) - (0.43*parseFloat(W)*parseFloat(W)))/(2*parseFloat(P)*parseFloat(PA))',
        7: '100*((2*parseFloat(W)*parseFloat(L)) - (0.43*parseFloat(W)*parseFloat(W)))/(parseFloat(P)*parseFloat(PA))'
    };
   
    var exp = exp_list[key];
    var a = Math.floor(10*(eval(exp)))/10;
    document.form1["r" + key].value = a;
    if (parseFloat(a) > 100) {
        alert('開孔率が100％を超えています');
    }
}

function calc_weight(){
    var B = document.form2.b.value;
    var T = document.form2.t.value;
    var H = document.form2.h.value;
    var D = document.form2.d.value;
    var K = document.form2.k.value;
    var M = document.form2.m.value;

    var a = (Math.round((B*T*H/1000*D/1000*((100-K)/100))*100))/100;
    document.form2.a.value = Math.floor(a*10)/10;
    document.form2.a2.value = Math.floor(10*a*M)/10;
}