[рони]

gross,

function number_good_view(user_num, after_point){
    if ((user_num-Math.floor(user_num))>0){ //если есть дробная часть
        user_num=user_num.toFixed(after_point).replace(/0+$/,"");

    }
     return user_num;

}
alert( number_good_view(0.000000006000, 10));