adding a line to an invoice form

[zinu]

hi to all,

i am new in asp.net.then i have a form in asp.net(vb) for an invoice bill.
i want to add the invoice
item row by row...each row containing item name,quatity,cost,tax,price..
in table i used a combo box for item name,tax,a textboxes for remaining fields..
first when i load the form i have 3 rows...
after that when user clicks an add button...i need to create new rows...at last when user press the submit button..i want to save the values
to databse...can u help me as aearly as possible.

her i just paste my html code...

<asp:Table runat ="server" ID="tbl_inv" HorizontalAlign ="Center"  cellspacing="0" cellpadding="2"  style="width: 85%; height: 100%;">
<asp:TableRow >
<asp:TableCell  height="101">
<div style="margin-top:10px;"> 
    <asp:Table runat ="server"  width="100%"  cellspacing="0" cellpadding="2" >
    <asp:TableRow >
    <asp:TableCell CssClass="bluebrd"><h1>New Invoice</h1></asp:TableCell>
    </asp:TableRow>
    <asp:TableRow>
    <asp:TableCell height="101" >
    <asp:table  runat ="server" width="100%"  cellspacing="3" cellpadding="0" style="height :100%; table-layout: auto;" >
        <asp:TableRow>
        <asp:TableCell  style ="width :25%"><strong>Client</strong> :</asp:TableCell>
        <asp:TableCell style ="width :25%">
        <asp:TextBox ID="TextBox1" runat="server" Width="192px"></asp:TextBox></asp:TableCell>
        <asp:TableCell style ="width :25%"><strong>Invoice number</strong> :</asp:TableCell>
        <asp:TableCell  style ="width :25%">
        <asp:TextBox ID="TextBox3" runat="server"></asp:TextBox></asp:TableCell>
        </asp:TableRow>
        <asp:TableRow>
        <asp:TableCell  style ="width :25%"><strong>Address</strong> :</asp:TableCell>
        <asp:TableCell rowspan="2"   style ="width :25%">
        &nbsp;<asp:TextBox ID="TextBox2" runat="server" Height="40px" TextMode="MultiLine"
                              Width="192px"></asp:TextBox>
        </asp:TableCell>
        <asp:TableCell  style ="width :25%"><strong>Date</strong> :</asp:TableCell>
        <asp:TableCell  style ="width :25%">
        <asp:TextBox ID="TextBox4" runat="server"></asp:TextBox></asp:TableCell>
        </asp:TableRow>
        <asp:TableRow >
        <asp:TableCell  style ="width :25%">
        <asp:LinkButton ID="LinkButton1" runat="server">edit</asp:LinkButton><a href="#"></a></asp:TableCell>
        <asp:TableCell  style ="width :25%"><strong>Discount</strong> :</asp:TableCell>
        <asp:TableCell  style ="width :25%">
        <asp:TextBox ID="TextBox5" runat="server"></asp:TextBox></asp:TableCell>
        </asp:TableRow>
     </asp:Table>
     </asp:TableCell>
     </asp:TableRow> 
     
      <asp:TableRow>
      <asp:TableCell style="height: 190px">
            <asp:Table runat ="server"  width="100%"  cellspacing="0" cellpadding="0">
            <asp:TableRow>
            <asp:TableCell  cssclass="bluebg whitefont" style="width :169px; height: 19px;"   >Item Name</asp:TableCell>
            <asp:TableCell style="width :214px; height: 19px;"  cssclass="bluebg whitefont">Description</asp:TableCell>
            <asp:TableCell style="width :10%; height: 19px;"  cssclass="bluebg whitefont">Unit cost</asp:TableCell>
            <asp:TableCell style="width :10%; height: 19px;"  cssclass="bluebg whitefont">Qty</asp:TableCell>
            <asp:TableCell style="width :10%; height: 19px;"  cssclass="bluebg whitefont">Tax</asp:TableCell>
            <asp:TableCell style="width :20%; height: 19px;" cssclass="bluebg whitefont">Price</asp:TableCell>
            </asp:TableRow>
            <asp:TableRow>
            <asp:TableCell style="height: 67px; width: 169px;">
            <asp:DropDownList ID="DropDownList2" runat="server">
            </asp:DropDownList>
            </asp:TableCell>
            <asp:TableCell  style="height: 67px; width: 214px;">
            <asp:TextBox ID="TextBox13" runat="server" TextMode="MultiLine"></asp:TextBox>&nbsp;<br />
            </asp:TableCell>
            <asp:TableCell style="width: 70px; height:67px;">
            <asp:TextBox ID="TextBox10" runat="server" Width="64px" Height="24px"></asp:TextBox></asp:TableCell>
            <asp:TableCell  style="height: 38px">
            <asp:TextBox ID="TextBox7" runat="server" Width="64px"></asp:TextBox></asp:TableCell>
            <asp:TableCell style="height: 67px">
            <asp:DropDownList ID="DropDownList5" runat="server">
             </asp:DropDownList></asp:TableCell>
             <asp:TableCell  style="height:67px">0.00</asp:TableCell>
             </asp:TableRow>
             <asp:TableRow>
             <asp:TableCell style="width: 169px; height: 67px;">
             <asp:DropDownList ID="DropDownList3" runat="server">
             </asp:DropDownList></asp:TableCell>
             <asp:TableCell  style="width: 214px; height:67px;">
             <asp:TextBox ID="TextBox12" runat="server" TextMode="MultiLine"></asp:TextBox><br />
             </asp:TableCell>
             <asp:TableCell  style="width: 70px; height: 67px;">
             <asp:TextBox ID="TextBox11" runat="server" Width="64px" Height="24px"></asp:TextBox></asp:TableCell>
             <asp:TableCell   style="height: 67px">
             <asp:TextBox ID="TextBox8" runat="server" Width="64px"></asp:TextBox></asp:TableCell>
             <asp:TableCell style="height: 67px">
             <asp:DropDownList ID="DropDownList6" runat="server">
             </asp:DropDownList></asp:TableCell>
              <asp:TableCell  style="height: 67px">0.00</asp:TableCell>
              </asp:TableRow>
              </asp:Table> 
        </asp:TableCell>
       </asp:TableRow>
       </asp:Table> 
       </div> 
       </asp:TableCell> 
       </asp:TableRow>
         
 </asp:Table>         
 
<asp:ImageButton ID="ImageButton1" runat="server" ImageUrl="~/imagez/plus1.jpg" />
<asp:LinkButton ID="lbtn_addline" runat="server">Addline</asp:LinkButton>

thanks a lot