How to make fixed header table inside scrollable div?

I want to make header of my table fixed. Table is present inside the scrollable div. Below is my code.

<div id="table-wrapper">
    <div id="table-scroll">
        <table bgcolor="white" border="0" cellpadding="0" cellspacing="0" id="header-fixed" width="100%" overflow="scroll" class="scrollTable">
            <thead>
                <tr>
                    <th>Order ID</th>
                    <th>Order Date</th>
                    <th>Status</th>
                    <th>Vol Number</th>
                    <th>Bonus Paid</th>
                    <th>Reason for no Bonus</th>
                </tr>
            </thead>
            <tbody>
                <tr>
                    <td><%=snd.getOrderId()%></td>
                    <td><%=snd.getDateCaptured()%></td>
                    <td><%=snd.getOrderStatus()%></td>
                    <td>Data Not Available</td>
                    <td>Data Not Available</td>
                    <td>Data Not Available</td>
                </tr>
            </tbody>
        </table>
    </div>
</div>

Below is my CSS, which I am using for the above div:

#table-wrapper {
    position:relative;
}

#table-scroll {
    height:250px;
    overflow:auto;  
    margin-top:20px;
}

#table-wrapper table {
    width:100%;
}

#table-wrapper table * {
    background:white;
    color:black;
}

#table-wrapper table thead th .text {
    position:absolute;   
    top:-20px;
    z-index:2;
    height:20px;
    width:35%;
    border:1px solid red;
}