Reading a CSV file using JQuery

Reading a CSV file using JQuery

HTML

<input id="upload" type="file">
<form id="csvForm">
    <input id="a"></input>
    <input id="b" ></input>
    <input id="c" ></input>
    <input id="d"></input>
</form>
    <button id="download">Download</button>
    
    <input id="a3" onblur="calculate()"></input>

JavaScript

document.getElementById("upload").addEventListener("change", upload, false);
document.getElementById("download").addEventListener("click", download, false);

function upload(e) {

    var data = null;
    var file = e.target.files[0];

    var reader = new FileReader();
    reader.readAsText(file);
    reader.onload = function (event) {
        var csvData = event.target.result;

        var parsedCSV = d3.csv.parseRows(csvData);

        parsedCSV.forEach(function (d, i) {
            if (i == 0) return true; // skip the header
            document.getElementById(d[0]).value = d[1];
        });

    }
}

function download(e) {
    
    data = [["id","value"]];
    
    var f = d3.selectAll("#csvForm > input")[0];
    
    f.forEach(function(d,i){
      	data.push([d.id, d.value]);
    });
    
    console.log(data);
    
    var csvContent = "data:text/csv;charset=utf-8,";
    data.forEach(function (d, i) {
        dataString = d.join(",");
        csvContent += i < data.length ? dataString + "\n" : dataString;
    });

    var encodedUri = encodeURI(csvContent);
    var link = document.createElement("a");
    link.setAttribute("href", encodedUri);
    link.setAttribute("download", "FormData.csv");
    link.click(); 
}
calculate = function()
{
    var resources = document.getElementById('a').value;
    var minutes = document.getElementById('b').value; 
    document.getElementById('a3').value = parseInt(resources)*parseInt(minutes);
}