How to Trigger Click Event of a Button in UserCont

Question

I have a ShoppingCart UserControl on MasterPage. I have a following functionality: User adds item to the cart. after clicking the button "Complete Sale" in UserControl the page is redirected to "CustomerInfo.aspx" and after filling the Customer information and clicking on submit which is on CustomerInfo.aspx page i want to call the "Complete Sale" click event of UserControl from "Customerinfo.aspx" page.

Customerinfo.aspx.cs

protected void btnSubmit_Click(object sender, EventArgs e)
    {
        try
        {
            bool val=false;
            int retVal = 0;
            CustomerBiz objCust = new CustomerBiz();

            objCust.FirstName = txtFirstName.Text.Trim();
            objCust.LastName = txtLastName.Text.Trim();
            objCust.Phone = txtPhone.Text.Trim();
            objCust.Email = txtEmail.Text.Trim();
            if (hdnCustomerID!=null && !string.IsNullOrEmpty(hdnCustomerID.Value) && hdnCustomerID.Value!="0")
                objCust.CustomerID = Convert.ToInt32(hdnCustomerID.Value);
            else
                objCust.CustomerID =0;
            retVal = objCust.AddCustomerInfo();
            if (retVal > 0)
            {
                //success     
                UserControl uch = Page.Master.FindControl("shpCart") as UserControl;
                Button lnkCheckOut=uch.FindControl("lnkCheckOut") as Button;
                lnkCheckOut.Text = "Found in Customer.aspx";
                //lnkCheckOut.Click += new EventHandler(lnkCheckOut.);
                lnkCheckOut.Text = "You Clicked";//Here Text of button in UserControl changes but how to call the ClickEvent of this button in Customerinfo.aspx page ?

                // completeBtn.Click += new EventHandler(btnSubmit_Click);
                Response.Redirect("Devices.aspx", true);
            }
            else
            { 
                //fail
            }
       }
        catch (Exception ex)
        {

        }
    }

Here the Button text changes in UserControl. But i am not able to call the Click event of this button from CustomerInfo.aspx (ContentPage) any suggestions?