How to bind dropdownlist with database value

using System.Data;
using System.Data.SqlClient;
using System.Configuration;

   
string _connStr = ConfigurationManager.ConnectionStrings["ConnStr"].ConnectionString;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
GetData();
}
}
 
private void GetData()
{
DataTable table = new DataTable();
// get the connection
using (SqlConnection conn = new SqlConnection(_connStr))
{
// write the sql statement to execute
string sql = "SELECT AutoId, FirstName + ' ' + LastName as FullName, Age, Active FROM PersonalDetail ORDER By AutoId";
// instantiate the command object to fire
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
// get the adapter object and attach the command object to it
using (SqlDataAdapter ad = new SqlDataAdapter(cmd))
{
// fire Fill method to fetch the data and fill into DataTable
ad.Fill(table);
}
}
}
// specify the data source for the DropDownList
dropDownList1.DataSource = table;
// bind the data now
dropDownList1.DataBind();
// specify the data source for the ListBox
listBox1.DataSource = table;
// bind the data now
listBox1.DataBind();
}

<select name="dropDownList1" id="dropDownList1">
<option value="3">Joe Elan</option>
<option value="5">Michael Sumakar</option>
<option value="10">Smith Modified Paul Modified</option>
<option value="22">Jesn Anil</option>
<option value="35">Jeff Janson</option>
<option value="36">Sheo Narayan</option>
<option value="37">Ammar Naqi</option>
</select>
 
<select size="4" name="listBox1" id="listBox1">
<option value="3">Joe Elan</option>
<option value="5">Michael Sumakar</option>
<option value="10">Smith Modified Paul Modified</option>
<option value="22">Jesn Anil</option>
<option value="35">Jeff Janson</option>
<option value="36">Sheo Narayan</option>
<option value="37">Ammar Naqi</option>
</select>