function Read_Data()
{
var str=0;
var Grid_Table = document.getElementById('<%=grid_list.ClientID%>');
for(var row=1; row<Grid_Table.rows.length; row++)
{
if(document.all)
str=str+Number(Grid_Table.rows[row].cells[3].innerText);
else
str=str+Number(Grid_Table.rows[row].cells[3].textContent);
}
alert(str);
return false;
}