Help with PlaceHolders and Aligning Controls

Hello all -
This is for the Web using C#

Yesterday i posted about creating controls dynamically and building tables. I decided to go a different direction.

I'm now using PlaceHolders.  I'm creating 7 controls on a click of a button and everytime the user clicks the Add button another 7 controls are created. it consists of 3 labels. 3 textboxes and 1 button.

How it works right now, all the controls are created in one PlaceHolder and it looks fine when they hit the Add button once. But when the button is hit for the second time it shows 12 controls on one row and 2 controls on another row.

I would like it to show 7 controls per row, this way it is all aligned.
If that isn't possible, is there a way to add the controls to a new PlaceHolder everytime the Add button is clicked.  
Also, when i click the Add button and fill out the three fields, then click the Add button again, the first field is blank but the other two fields still have the text i entered.

Thanks a lot in advance. My code is below.

protected void Page_Load(object sender, EventArgs e)
    {
               CreateControls();        
    }

protected void btnAdd_Click(object sender, EventArgs e)
{
        int count = 0;
        if (ViewState["count"] != null)
        {
            count = (int)ViewState["count"];
        }
        count++;
               
        ViewState["count"] = count;
        CreateControls();
}

private void CreateControls()
    {

        int count = 0;
        if (ViewState["count"] != null)
        {
            count = (int)ViewState["count"];
        }

        while (PlaceHolder1.Controls.Count < count * 7)
        {
            // -----INVOICE-----
           //Control One
            Label lblInvoice = new Label();
            PlaceHolder1.Controls.Add(lblInvoice);
            lblInvoice.ID = "lblInvoice" + PlaceHolder1.Controls.Count.ToString();
            lblInvoice.Text = "Invoice #:";

            //Control Two
            TextBox txtInvoice = new TextBox();
            PlaceHolder1.Controls.Add(txtInvoice);
            txtInvoice.ID = "txtInvoice:" + PlaceHolder1.Controls.Count.ToString();
            txtInvoice.Text = "";
            txtInvoice.Height = 18;

            // -----AMOUNT-----
            //Control Three
            Label lblAmount = new Label();
            PlaceHolder1.Controls.Add(lblAmount);
            lblAmount.ID = "lblAmount" + PlaceHolder1.Controls.Count.ToString();
            lblAmount.Text = "Amount:";

            //Control Four
            TextBox txtAmount = new TextBox();
            PlaceHolder1.Controls.Add(txtAmount);
            txtAmount.ID = "txtAmount" + PlaceHolder1.Controls.Count.ToString();
            txtAmount.Text = "";
            txtAmount.Height = 18;

            // -----DATE-----
            //Control Five
            Label lblDateRecieved = new Label();
            PlaceHolder1.Controls.Add(lblDateRecieved);
            lblDateRecieved.ID = "lblDateRecieved" + PlaceHolder1.Controls.Count.ToString();
            lblDateRecieved.Text = "Date:";

            //Control SIx
            TextBox txtDateRecieved = new TextBox();
            PlaceHolder1.Controls.Add(txtDateRecieved);
            txtDateRecieved.ID = "txtDateRecieved" + PlaceHolder1.Controls.Count.ToString();
            txtDateRecieved.Text = "";
            txtDateRecieved.Height = 18;

            //Control Seven
            Button btnCalendar = new Button();
            PlaceHolder1.Controls.Add(btnCalendar);
            btnCalendar.ID = "btnCalendar" + PlaceHolder1.Controls.Count.ToString();
            btnCalendar.BackColor = System.Drawing.Color.White;
            btnCalendar.CssClass = "calendarImage";
            btnCalendar.Width = 27;
        }
       
    }