how to validate user with (userid,password,IP address)

Hi

 

I have a problem of login on the basis of IP.

 

Suppose we have two table 

 

1) contains: Username,Pass

2) Contains : UserName, IP

 

Single user can have multiple IP Assign

 

when the user enters Username and Password I have to check out IP address matches with

Ip provided to user in table 2

 

If Username,Ip,and Pass matches there will be successful login

 

 

I have created a function to get IP :

 

 

public void GetIPAddress(out string userip)
{
userip = Request.UserHostAddress;
if (Request.UserHostAddress != null)
{
Int64 macinfo = new Int64();
string macsrc = macinfo.ToString("X");
if (macsrc == "0")
{
Label1.Text = userip;
}
}
}

 

but further I don't  know that how to do it

 

thanks in advance