Design a Survey Form using HTML CSS and JavaScript

// Script.js
// Adding event listener to the form element
document
    .getElementById("surveyForm")
    .addEventListener(
        "submit",
        function (event) {
            // PreventDefault() is used to avoid
            // Refreshing of browser while submit
            event.preventDefault();

            let nameField =
                document.getElementById(
                    "name"
                );
            let ageField =
                document.getElementById(
                    "age"
                );
            let errorText =
                document.getElementById(
                    "errorText"
                );

            let name = nameField.value;
            let age = ageField.value;

            // Creating a regular expression for 
            // Name field
            let Regex = /^[A-Za-z ]+$/;

            // If name does not matches the 
            // Regular expression
            if (!name.match(Regex)) {
                nameField.classList.add(
                    "error"
                );
                errorText.innerHTML =
                    `Name field should only contain 
                     English alphabets and spaces`;
                errorText.classList.add(
                    "errorText"
                );
                return;
            }

            // Check whether age is between 1 and 150
            else if (
                isNaN(age) ||
                age < 1 ||
                age > 150
            ) {
                ageField.classList.add(
                    "error"
                );
                errorText.innerHTML =
                    `Age should only contain valid
                     values ( 1 - 150 )`;
                errorText.classList.add(
                    "errorText"
                );
                return;
            }

            // Removing red border in name field
            if (
                nameField.classList.contains(
                    "error"
                )
            )
                nameField.classList.remove(
                    "error"
                );

            // Removing red border in age field
            if (
                ageField.classList.contains(
                    "error"
                )
            )
                ageField.classList.remove(
                    "error"
                );

            // Adding success message and styles
            errorText.innerHTML =
                "Submitted Successfully";
            errorText.classList.add(
                "successText"
            );

            const formData =
                new FormData(
                    event.target
                );
            const formValues = {};

            // Storing each values in the object
            formData.forEach(
                (value, key) => {
                    formValues[key] =
                        value;
                }
            );

            // Calling convert function
            const csvContent =
                convertToCSV(
                    formValues
                );
            const blob = new Blob(
                [csvContent],
                { type: "text/csv" }
            );

            // Creating a link for downloading
            // Excel sheet
            const link =
                document.createElement(
                    "a"
                );
            link.href =
                window.URL.createObjectURL(
                    blob
                );
            link.download =
                "survey_data.csv";
            link.click();

            // Reseting the form after certain
            // Timeout 2000ms => 2s
            setTimeout(
                document
                    .getElementById(
                        "surveyForm"
                    )
                    .reset(),
                2000
            );
        }
    );

// Function to convert object to csv
function convertToCSV(objArr) {
    const array =
        typeof objArr !== "object"
            ? JSON.parse(objArr)
            : objArr;
    let result = "";

    // Add commas to make it as csv
    const header =
        Object.keys(array).join(",") +
        "\n";
    result += header;

    for (const item in array) {
        if (
            array.hasOwnProperty(item)
        ) {
            result += array[item] + ",";
        }
    }
    result = result.slice(0, -1);
    result += "\n";

    return result;
}