datalist : cell size is changed at runtime when i refresh the page

[diya0076]

hi my problem is when i 1st run the webpage content of datalist size of cell is diffrent n when again i refresh the page it becomes diffrent..

this difference is occurred in width of the cells of datalist control..

here is my code..

[B]   <asp:SqlDataSource ID="SqlDataSource1" 
      runat="server" 
     ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
     SelectCommand="select * from product where pcode like 'dtv%'">
</asp:SqlDataSource>

<center>

    <asp:DataList ID="DataList1" runat="server" DataSourceID="SqlDataSource1" RepeatColumns="3"
        RepeatDirection="Horizontal" height="80%" Width="80%" OnSelectedIndexChanged="DataList1_SelectedIndexChanged" BackColor="#DEBA84" BorderColor="#DEBA84" BorderStyle="None" BorderWidth="1px" CellPadding="0" CellSpacing="2" GridLines="Both" >

        <ItemTemplate>
            pcode:
            <asp:Label ID="pcodeLabel" runat="server" Text='<%# Eval("pcode") %>'></asp:Label><br />
            <br />
            pname:
            <asp:Label ID="pnameLabel" runat="server" Text='<%# Eval("pname") %>'></asp:Label><br />
            <br />
            &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<asp:ImageButton ID="ImageButton1" runat="server" PostBackUrl='<%# Eval("purl","display.aspx?purl=items/{0}") %>' ImageUrl='<%# Eval("purl","items/{0}") %>' Height="30%" Width="30%" BorderWidth="1px" />
            &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
            <br />
            <br />
            <asp:LinkButton ID="LinkButton1" PostBackUrl='<%# Eval("purl","display.aspx?purl=items/{0}") %>' runat="server" Text="Full Size"></asp:LinkButton>
		<br />
            <br />
            price:
            <asp:Label ID="priceLabel" runat="server" Text='<%# Eval("price") %>'></asp:Label>
         
            disc:
            <asp:Label ID="discLabel" runat="server" Text='<%# Eval("disc") %>'></asp:Label><br />
            <br />
        </ItemTemplate>
        <FooterStyle BackColor="#F7DFB5" ForeColor="#8C4510" />
        <ItemStyle BackColor="#FFF7E7" ForeColor="#8C4510" />
        <SelectedItemStyle BackColor="#738A9C" Font-Bold="True" ForeColor="White" />
        <HeaderStyle BackColor="#A55129" Font-Bold="True" ForeColor="White" />
    </asp:DataList>

 </center>
[/B]

why its happening???