gridview textbox insert value after refresh label value

hello,

gridview textbox insert value after refresh another div label value in c# and

aspx.cs page get refresh new value .

code(aspx):-

CellPadding="5" CellSpacing="1" GridLines="None" BorderWidth="0" OnRowDeleting="cartgrid_RowDeleting"
OnRowDataBound="cartgrid_RowDataBound" AutoGenerateColumns="False">

<%#"

"%>

Font-Names="Verdana" ForeColor="#666666" />

Name

Product Code #

Font-Names="Verdana" ForeColor="#666666" />

Size

disabled="disabled" />

Font-Names="Verdana" ForeColor="#666666" />

Comment

Font-Names="Verdana" ForeColor="#666666" />

Price($)

$

Font-Names="Verdana" ForeColor="#666666" />

Font-Names="Verdana" ForeColor="#666666" />

Qty

value='<%# Eval("qty") %>' runat="server" />

runat="server" readonly="readonly" />

ForeColor="#666666" />

Total

$

Font-Names="Verdana" ForeColor="#666666" />

visible="true">
Grand Total : $

code(aspx.cs)

protected void imgbtncheckout_Click(object sender, EventArgs e) //(object sender, EventArgs e)
{
try
{

Int16 checkamount = 250;
float bindvaluveamount = float.Parse(lblshoppingamt.Text);

note:- get value but old value get... so plz help me how to new value get.
if (bindvaluveamount >= checkamount)
{

if (Session["userid"] != null)
{
......

......

......
}

}