btc-e script

var balance_btc = 0.4345, balance_usd = 0;
var min_diff = 1;
var last_bid_price = parseFloat($('#max_price').html());
var last_ask_price = null;
var is_selling = false;

sell(last_bid_price,balance_btc);
setInterval(function(){
    if(is_selling){
        var curr_bid_price = parseFloat($('#max_price').html());
        if((curr_bid_price-last_ask_price)>=min_diff){
            is_selling = false;
            sell(curr_bid_price,balance_btc);
        }
    }else {
        var curr_ask_price = parseFloat($('#min_price').html());
        if((curr_ask_price-last_bid_price)<=-min_diff){
            is_selling = true;
            buy(curr_ask_price,balance_usd);
        }
    }
    console.log("BALANCE BTC: "+balance_btc+"\nBALANCE USD: "+balance_usd+"\nLAST BID PRICE: "+
        last_bid_price+"\nLAST ASK PRICE: "+last_ask_price+"\n");
},1000);

function sell(price, amount){
    balance_btc = 0;
    balance_usd = parseFloat((amount * price).toFixed(2));
    last_bid_price = price;
    $('#b_btc').val(amount);
    $('#b_price').val(price);
    ex_trade("sell",1);
}
function buy(price, amount){
    balance_usd = 0;
    balance_btc = parseFloat((amount / price).toFixed(8));
    last_ask_price = price;
    $('#s_btc').val(amount);
    $('#s_price').val(price);
    ex_trade("buy",1);
}