动态添加控件ASP.NET

int textnum ;
int btnnum ;
int listnm;
        int dlistnum;

textnum=Convert.ToInt32(this.TextBox1.Text);
btnnum=Convert.ToInt32(this.TextBox2.Text);
listnm=Convert.ToInt32(this.TextBox3.Text);
dlistnum=Convert.ToInt32 (this.TextBox4.Text);


for(int i=0;i<textnum;i++)
{
    this.Panel1.Controls.Add(new TextBox());
this.Panel1.Controls.Add(new TextBox());


}
for(int j=0; j<btnnum;j++)
{
this.Panel1.Controls.Add(new Button());
this.Panel1.Controls.Add(new Button());


}
for(int k=0; k<listnm;k++)
{
    this.Panel1.Controls.Add(new ListBox());
this.Panel1.Controls.Add(new ListBox());