Web Forms :: Server Side Button Click Must Perform Before Client?

This is my aspx pages button properties:

<asp:Button runat="server" ID="cmdConfirm" Text="Select
Customer"
ValidationGroup="ValidateId" Height="26px" onclick="cmdSave_Click"/
Now on my Page_Load I have:
protected void Page_Load(object sender, System.EventArgs
e)
{
Name = Request.QueryString[0];
LoadCustomer();
cmdConfirm.Attributes.Add("onClick", "update("
+ Name + ");");
Conn.Close();
}

This is my button click for Select Customer button.

protected void cmdSave_Click(object sender, EventArgs
e)
{
RecordChanges();
}

Now I must run cmdSave_Click() before the cmdConfirm.Attributes.Add even though both is for same button anyway. I know that client side script will try to run first but I must run the cmdSave_Click event first to save the data. Aftre that cmdConfirm.Attributes will send the Name to the next page using a Javascript function where the stored values(stored using cmdSave_Click) will be used. I have no other choice. I cannot run the Javascript function first as it will happen before the data is stored. And also I cannot use another page as all has to be performed in one page so that user will not have to click Save twice. Can anyone tell me How I can delay the cmdConfirm.Attributes.Add until the cmdSave_Click is performed.