Textbox problems

Hi guys

I want the user to click on a button that allows him to have his postal address the same as his physical address. I have tried the following combinations of cade and some of them returns errors and other don't do anything

 
protected void sameaddressbutton_Click(object sender, EventArgs e)
{
TextBox pstreet = ((TextBox)CreateUserWizard1.FindControl("TextBoxPostalStreetAddress"));
TextBox street = ((TextBox)CreateUserWizard1.FindControl("TextBoxAddressStreet"));
pstreet = street;
}

protected void sameaddressbutton_Click(object sender, EventArgs e)
{
CreateUserWizard1.FindControl("TextBoxPostalStreetAddress&q ...