// Air flow (CFM) = (Horsepower × 0.625) × 1.1104
var cfm_calc = function() {
    var hp1, cfm1;
    hp1 = Number(document.airflow.HP1.value);
    cfm1 = (hp1 * 0.625) * 1.1104;
    document.airflow.CFM1.value = Math.round(cfm1 * 100) / 100;
    return cfm1;
};
// Horsepower = (Air flow × 1.6) × 0.9 
var hp_calc = function() {
    var hp2, cfm2;
    cfm2 = Number(document.hp.CFM2.value);
    hp2 = (cfm2 * 1.6) * 0.9;
    document.hp.HP2.value = Math.round(hp2 * 100) / 100;
    return hp2;
};