<configuration>
<system.web>
<authentication mode = "Forms">
<forms name="CHeck" protection="All" timeout="10">
<credentials passwordFormat = "Clear">
<user name ="abc" password = "123"/>
</credentials>
</forms>
</authentication>
<authorization>
<deny users = "?"/>
</authorization>
</system.web>
</configuration>

Sub doLogin(sender as object, e as eventargs)
If FormsAuthentication.Authenticate(uname.text, pword.text) Then
FormsAuthentication.SetAuthCookie(uname.text, true)
Response.Redirect("ww_executive.htm")
Else
Response.Redirect("login.aspx")
End If
End Sub

function run() {
       if (document.cookie.indexOf('CHeck')==-1){
       location.href="login.aspx";
       }
       else if (document.cookie.indexOf("CHeck")!=null) {
       location.href="ww_executive.htm";
       }
}

<configuration>
  <system.web>
    <authentication mode="Forms">
      <forms name=".MYCOOKIE" 
             loginUrl="login.aspx" 
             protection="All" 
             timeout="30" 
             path="/"/> 
    </authentication>
    <authorization>
      <deny users="?" />
    </authorization>
  </system.web>
</configuration>

        <credentials passwordFormat="Clear">
          <user name="user1" password="password1"/>
          <user name="user2" password="password2"/>
          <user name="user3" password="password3"/>
        </credentials>

void Login_Click(Object sender, EventArgs E) 
{
  // authenticate user: this sample authenticates 
  // against users in your app domain's web.config file
  if (FormsAuthentication.Authenticate(username.Value,
                                       password.Value))
  {
    FormsAuthentication.RedirectFromLoginPage(username.Value, true);
   //the boolean persists the cookie.
  } 
  else 
  {
    lblResults.Text = "Invalid Credentials: Please try again";
  }
}