internet explorer control

[C# Programming]

I have made a little program that when i open the IE and puts url google.com i should go to microsoft.com for exemple in the same window, but it opens a new ie windows and goes to the site can someone help.

the code

detect new ie open
private void Form1_Load(object sender, EventArgs e)
{
shellWindows.WindowRegistered += new SHDocVw.DShellWindowsEvents_WindowRegisteredEventHandler(detect_ie);

}

private void detect_ie(int z)
{
foreach (SHDocVw.InternetExplorer ie in shellWindows)
{

ie.BeforeNavigate2 += new SHDocVw.DWebBrowserEvents2_BeforeNavigate2EventHandler(ie_BeforeNavigate2);



}

}



Detects the url open and goes to new url


void ie_BeforeNavigate2(object pDisp, ref object URL, ref object Flags, ref object TargetFrameName, ref object PostData, ref object Headers, ref bool Cancel)
{

object Flags2 = Flags;
object TargetFrameName2 = TargetFrameName;
ur=URL.ToString();

int tamanho =0;
int cont =0;
while (cont < 3)
{
tamanho = tamanho + 1;
if (ur[tamanho] == '/')
{
cont = cont + 1;
}
}
ur = ur.Substring(0, tamanho);

if (ur == "www.microsoft.com")
{
URL="www.google.com";
SHDocVw.InternetExplorer ie = new SHDocVw.InternetExplorer();
URL = "www.google.com".ToString();
ie.Navigate2(ref URL, ref Flags, ref TargetFrameName, ref PostData, ref Headers);
}