diff --git a/README.md b/README.md
index 6f5b6dc..0f51e7e 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,10 @@
 # exchange-rate-export
-Get data from BIDV and export to Excel format
+Get data from BIDV[https://bidv.com.vn/vn/ty-gia-ngoai-te] and export to Excel format.
+
+Features:
+- Allow select time range.
+- Export to Excel.
+
+Use these api:
+- https://bidv.com.vn/ServicesBIDV/ExchangeDetailSearchTimeServlet
+- https://bidv.com.vn/ServicesBIDV/ExchangeDetailServlet
\ No newline at end of file
diff --git a/index.html b/index.html
new file mode 100644
index 0000000..743bfb9
--- /dev/null
+++ b/index.html
@@ -0,0 +1,266 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Exchange Rate Export</title>
+    <style>
+        body {
+            font-family: Arial, sans-serif;
+            margin: 40px;
+            background: #f7f7f7;
+        }
+        .container {
+            background: #fff;
+            padding: 24px;
+            border-radius: 8px;
+            box-shadow: 0 2px 8px rgba(0,0,0,0.07);
+            max-width: 700px;
+            margin: auto;
+        }
+        h1 {
+            text-align: center;
+        }
+        label {
+            margin-right: 8px;
+        }
+        input[type="date"] {
+            margin-right: 16px;
+            padding: 4px 8px;
+        }
+        button {
+            padding: 8px 16px;
+            margin-right: 8px;
+            border: none;
+            border-radius: 4px;
+            background: #007bff;
+            color: #fff;
+            cursor: pointer;
+            font-size: 1rem;
+        }
+        button:disabled {
+            background: #aaa;
+            cursor: not-allowed;
+        }
+        table {
+            width: 100%;
+            border-collapse: collapse;
+            margin-top: 24px;
+        }
+        th, td {
+            border: 1px solid #ddd;
+            padding: 8px;
+            text-align: center;
+        }
+        th {
+            background: #007bff;
+            color: #fff;
+        }
+        .loading {
+            text-align: center;
+            margin-top: 20px;
+            color: #007bff;
+        }
+        .error {
+            color: red;
+            text-align: center;
+            margin-top: 20px;
+        }
+    </style>
+</head>
+<body>
+    <div class="container">
+        <h1>Exchange Rate Export (USD)</h1>
+        <div style="margin-bottom: 20px;">
+            <label for="start-date">Start Date:</label>
+            <input type="date" id="start-date">
+            <label for="end-date">End Date:</label>
+            <input type="date" id="end-date">
+            <button id="fetch-btn">Fetch</button>
+            <button id="export-btn" disabled>Export CSV</button>
+        </div>
+        <div id="status"></div>
+        <table id="result-table" style="display:none;">
+            <thead>
+                <tr>
+                    <th>Date</th>
+                    <th>nameVI</th>
+                    <th>muaTm</th>
+                    <th>muaCk</th>
+                    <th>currency</th>
+                    <th>nameEN</th>
+                    <th>ban</th>
+                </tr>
+            </thead>
+            <tbody></tbody>
+        </table>
+    </div>
+    <script>
+        const fetchBtn = document.getElementById('fetch-btn');
+        const exportBtn = document.getElementById('export-btn');
+        const startDateInput = document.getElementById('start-date');
+        const endDateInput = document.getElementById('end-date');
+        const statusDiv = document.getElementById('status');
+        const table = document.getElementById('result-table');
+        const tbody = table.querySelector('tbody');
+        let results = [];
+
+        function formatDate(date) {
+            // Format as dd/MM/yyyy
+            const d = new Date(date);
+            const day = String(d.getDate()).padStart(2, '0');
+            const month = String(d.getMonth() + 1).padStart(2, '0');
+            const year = d.getFullYear();
+            return `${day}/${month}/${year}`;
+        }
+
+        function getDateRange(start, end) {
+            const dates = [];
+            let current = new Date(start);
+            const last = new Date(end);
+            while (current <= last) {
+                dates.push(new Date(current));
+                current.setDate(current.getDate() + 1);
+            }
+            return dates;
+        }
+
+        async function fetchNamerecord(dateStr) {
+            const url = 'https://bidv.com.vn/ServicesBIDV/ExchangeDetailSearchTimeServlet';
+            const payload = `date=${encodeURIComponent(dateStr)}`;
+            try {
+                const res = await fetch(url, {
+                    method: 'POST',
+                    headers: {
+                        'Content-Type': 'application/x-www-form-urlencoded',
+                    },
+                    body: payload
+                });
+                if (!res.ok) throw new Error('API 1 error');
+                const data = await res.json();
+                if (data.status !== 1 || !data.data || !data.data.length) return null;
+                // Get the latest (max time) record
+                let latest = data.data[0];
+                for (const rec of data.data) {
+                    if (rec.time > latest.time) latest = rec;
+                }
+                return latest.namerecord;
+            } catch (e) {
+                return null;
+            }
+        }
+
+        async function fetchUSD(dateStr, namerecord) {
+            const url = 'https://bidv.com.vn/ServicesBIDV/ExchangeDetailServlet';
+            const payload = `date=${encodeURIComponent(dateStr)}&time=${namerecord}`;
+            try {
+                const res = await fetch(url, {
+                    method: 'POST',
+                    headers: {
+                        'Content-Type': 'application/x-www-form-urlencoded',
+                    },
+                    body: payload
+                });
+                if (!res.ok) throw new Error('API 2 error');
+                const data = await res.json();
+                if (data.status !== 1 || !data.data) return null;
+                // Find USD (currency === 'USD')
+                const usd = data.data.find(item => item.currency === 'USD');
+                if (!usd) return null;
+                return {
+                    nameVI: usd.nameVI,
+                    muaTm: usd.muaTm,
+                    muaCk: usd.muaCk,
+                    currency: usd.currency,
+                    nameEN: usd.nameEN,
+                    ban: usd.ban
+                };
+            } catch (e) {
+                return null;
+            }
+        }
+
+        function renderTable(data) {
+            tbody.innerHTML = '';
+            for (const row of data) {
+                const tr = document.createElement('tr');
+                tr.innerHTML = `
+                    <td>${row.date}</td>
+                    <td>${row.nameVI}</td>
+                    <td>${row.muaTm}</td>
+                    <td>${row.muaCk}</td>
+                    <td>${row.currency}</td>
+                    <td>${row.nameEN}</td>
+                    <td>${row.ban}</td>
+                `;
+                tbody.appendChild(tr);
+            }
+            table.style.display = data.length ? '' : 'none';
+        }
+
+        function exportCSV(data) {
+            const header = ['Date', 'nameVI', 'muaTm', 'muaCk', 'currency', 'nameEN', 'ban'];
+            const rows = [header];
+            for (const row of data) {
+                rows.push([
+                    row.date,
+                    row.nameVI,
+                    row.muaTm,
+                    row.muaCk,
+                    row.currency,
+                    row.nameEN,
+                    row.ban
+                ]);
+            }
+            const csvContent = rows.map(r => r.map(cell => '"' + String(cell).replace(/"/g, '""') + '"').join(',')).join('\r\n');
+            const blob = new Blob([csvContent], { type: 'text/csv' });
+            const url = URL.createObjectURL(blob);
+            const a = document.createElement('a');
+            a.href = url;
+            a.download = 'usd_exchange_rates.csv';
+            document.body.appendChild(a);
+            a.click();
+            document.body.removeChild(a);
+            URL.revokeObjectURL(url);
+        }
+
+        fetchBtn.onclick = async () => {
+            const start = startDateInput.value;
+            const end = endDateInput.value;
+            if (!start || !end) {
+                statusDiv.innerHTML = '<div class="error">Please select both start and end dates.</div>';
+                return;
+            }
+            if (start > end) {
+                statusDiv.innerHTML = '<div class="error">Start date must be before or equal to end date.</div>';
+                return;
+            }
+            statusDiv.innerHTML = '<div class="loading">Fetching data, please wait...</div>';
+            fetchBtn.disabled = true;
+            exportBtn.disabled = true;
+            results = [];
+            renderTable([]);
+            const dates = getDateRange(start, end);
+            for (let i = 0; i < dates.length; i++) {
+                const dateObj = dates[i];
+                const dateStr = formatDate(dateObj);
+                statusDiv.innerHTML = `<div class=\"loading\">Fetching: ${dateStr} (${i+1}/${dates.length})</div>`;
+                const namerecord = await fetchNamerecord(dateStr);
+                if (!namerecord) continue;
+                const usd = await fetchUSD(dateStr, namerecord);
+                if (usd) {
+                    results.push({ date: dateStr, ...usd });
+                    renderTable(results);
+                }
+            }
+            statusDiv.innerHTML = results.length ? '' : '<div class="error">No data found for the selected range.</div>';
+            fetchBtn.disabled = false;
+            exportBtn.disabled = results.length === 0;
+        };
+
+        exportBtn.onclick = () => {
+            if (results.length) exportCSV(results);
+        };
+    </script>
+</body>
+</html>