var mode = 0;

function btn() {

var item = document.getElementById("item").value;

var qty = document.getElementById("qty").value;

var rate = document.getElementById("rate").value;

var discount = document.getElementById("dis").value;

var netAmt = document.getElementById("netAmt").value;

var netAmt = (qty * rate) - (qty * rate * discount / 100);

document.getElementById("netAmt").innerHTML = "net Amt " + netAmt;

}

function update(index) {

mode = index;

var row = document.getElementsByClassName("mid-col")[0].rows[index];

document.getElementById("bttn").innerHTML = "Update";

var form = document.forms[0];

var item = form.item;

var qty = form.qty;

var rate = form.rate;

var discount = form.discount;

var row = document.getElementsByClassName("mid-col")[0].rows[index];

item.value = row.cells[1].innerHTML;

qty.value = row.cells[2].innerHTML;

rate.value = row.cells[3].innerHTML;

discount.value = row.cells[4].innerHTML;

}

function btn1() {

var tbl = document.getElementsByClassName("mid-col")[0];

var r;

var row;

if (mode > 0) {

row = tbl.rows[mode];

r = mode;

mode = 0;

document.getElementById("bttn").innerHTML = "Add";

}

else {

r = tbl.rows.length;

row = tbl.insertRow(r);

}

var form = document.forms[0];

var item = form.item.value;

var qty = form.qty.value;

var rate = form.rate.value;

var discount = form.dis.value;

var netAmount = (qty * rate) - (qty * rate * discount / 100);

var data = "<td onclick='update(" + r + ")'>" + r + "</td>"

+ "<td onclick='update(" + r + ")'>" + item + "</td>"

+ "<td onclick='update(" + r + ")'>" + qty + "</td>"

+ "<td onclick='update(" + r + ")'>" + rate + "</td>"

+ "<td onclick='update(" + r + ")'>" + discount + "</td>"

+ "<td onclick='update(" + r + ")'>" + netAmount + "</td>"

row.innerHTML = data;

var amount = 0;

var discount1 = 0;

var netamount1 = 0;

for (i = 1; i < tbl.rows.length; i++) {

var amountP = tbl.rows[i].cells[2].innerHTML * tbl.rows[i].cells[3].innerHTML;

var discountP = (amountP / 100) * tbl.rows[i].cells[4].innerHTML;

var netAmtP = (amountP - discountP);

amount += amountP;

discount1 += discountP;

netamount1 += netAmtP;

}

document.getElementById("amount").innerHTML = amount;

document.getElementById("discount1").innerHTML = discount1;

document.getElementById("netamount1").innerHTML = netamount1;

}