Dynamic created textbox/label visibility destroyed when i do the next click event....

public partial class Products : System.Web.UI.Page 
{ 
public static Label lblCat,lblSubcat; 
public static TextBox txtCat, txtSubCat; 
string _Cat;// stores new Sub cat 
string _SubCat;

protected void lnkCat_Click(object sender, EventArgs e) 
{
Panel2.Visible = false; Panel1.Visible = true;
lblCat = new Label(); 
lblCat.Text = "Enter new Category: ";
PHcat.Controls.Add(lblCat); 
lblCat.EnableViewState = true; 
txtCat = new TextBox(); 
_Cat = txtCat.Text; 
PhtxtCat.Controls.Add(txtCat);
} 

protected void lnkSubCat_Click(object sender, EventArgs e) 
{ 
Panel1.Visible = true; 
Panel2.Visible = true; 
lblSubcat = new Label(); 
lblSubcat.Text = "Enter new Sub-Category: ";
PHsubCat.Controls.Add(lblSubcat); 
txtSubCat = new TextBox(); 
_SubCat = txtSubCat.Text; 
PhtxtSubCat.Controls.Add(txtSubCat); 
}
}

Here,my problem again is when i click on 'Create Category' link button (lnkCat_Click) dynamically its label and textbox is displayed for category and i have another link button for creating 'SuB-category' and when i click (lnkSubCat_Click) on that button for 'Create Sub category' THE FIRST DYNAMIC CREATED (FOR CATEGORY) LABEL AND TEXTBOX ARE REMOVED.

HERE I WANT TO HOLD THAT DYNAMIC CREATED(CAT AND SUB-CAT) SHOULD BE DISPLAYED TILL I CLICK ON SUBMIT BUTTON ON THE SAME PAGE!

I have two link button to create cat and sub-cat!

CAN U PLEASE HELP ON THIS MATTER? AND IS THIS POSSIBLE?

THANK YOU...EXPECTING A REPLY!