I'm retarded v2

var bet = document.getElementsByClassName('fifty')[0].children[0].children[0].value;

var one = document.getElementsByClassName('gamble')[0].children[0];
one.innerHTML+='<button onclick="double()">DOUBLE</button><button onclick="base()">BASE BET</button><h4>If you ave any questions contact me: nilmar1905@gmail.com</h4><h5 style="color:red">Sometimes you have to type amount for the first time manually. I`m trying to fix that.</h5>'
var c = 0;

function double(){
	bet = document.getElementsByClassName('fifty')[0].children[0].children[0].value;
    bet = bet*2;
    number(bet);
	c++
}

function base(){
    while(c >= 1){
        c--;
        bet = bet/2;
	}
    number(bet);
}

function number(betv){
var ein = document.getElementsByClassName('fifty')[0].children[0].children[0];
ein.value= betv;
};