How to Match user inputed data from database table

 I have simple database table with username,password & others
All i want is that when i input username&password in page it should match with my database table (name userreg) and if it matches then it redirects to other location else show denied error
i tried  this code from book
if(Membership.ValidateUser(txtuname.Text, txtpw.Text))


{
Response.Write("Correct username and password");
}
{Response.Write("Wroung username or password");}
BUT EVENIF I PUT WRITE USERNAME& PASSWORD IT DISPLAYS WROUNG PASSWORD & I HAVNOT CREATED DATABASE CONNECTION FOR ABOVE CODE ...