how can i keep my user control ?

Hi everyone

this is my page load code then when i wantto edit my data

protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
{ DataTable dtAttach = Donate.GetMatDonationAttach(SID);
{
if (dtAttach.Rows.Count > 0)
{
for (int i = 0; i <= dtAttach.Rows.Count - 1; i++)
{
Control tempControl = this.Page.LoadControl("UC/UC.ascx");
((ASP.sysadmin_credit_donationmaterial_uc_uc_ascx)tempControl).EquipmentName = dtAttach.Rows[i]["ObjName"].ToString();
((ASP.sysadmin_credit_donationmaterial_uc_uc_ascx)tempControl).Quantity = dtAttach.Rows[i]["Quantity"].ToString();
((ASP.sysadmin_credit_donationmaterial_uc_uc_ascx)tempControl).UnitPrice = dtAttach.Rows[i]["UnitPrice"].ToString();
attachSID = Convert.ToInt32(dtAttach.Rows[i]["SID1"].ToString());
pHolder.Controls.Add(tempControl);
}
}
}
}
}

then add another usercontrol on my page, but loaded data automatically remove on the my page

this is my adding user control button

how can i resolve when i add new usercontrol then keep old usercontrol and data ??