VS2005: Formview insert mode - Fill with initial value

Use the FindControl method to automatically fill your controls:

protected void FormView1_PreRender(object sender, EventArgs e)
{
string strDefaultProdName = "Product name";
if (FormView1.CurrentMode == FormViewMode.Insert &&
((TextBox)FormView1.FindControl("ProductNameTextBox")).Text.Length==0)
((TextBox)FormView1.FindControl("ProductNameTextBox")).Text =
strDefaultProdName;
}