html file call with php script

i have written a php script which check user authetication for the specific data. The database is MYSQL.
i wnat to call different html files like if the user is authentic it will go to the datbase file. if he is new user he should go to sign up.

should i use link function if so how.<?


if ($mem_name)
{

if($mem_pswd)
{
$db = mysql_connect("localhost", "mchayani", "Avirat")or die("Unable to connect to SQL server");

mysql_select_db("savdhan_com",$db);

$result = mysql_query ("SELECT * FROM mem_data WHERE Usr_name = '".$HTTP_POST_VARS["mem_name"]."'", $db);

if ( $myrow = mysql_fetch_array ($result) )
{
if ( !strcmp($mem_pswd, $myrow["Password"]))
{

if (!strcasecmp( "y", $myrow["flag"]) )
{
// I WOULD LIKE TO DISPALY ANOTHER HTML/PHP FILE
echo "Your Account has been activated" ;
exit();
}
else
{
// I WOULD LIKE TO DISPALY ANOTHER HTML/PHP FILE

echo "Your Account is not yet activated" ;
exit () ;
}
}
else
{
// I WOULD LIKE TO DISPALY ANOTHER HTML/PHP FILE
echo "Retype your password";
}
}
else
{
// I WOULD LIKE TO DISPALY ANOTHER HTML/PHP FILE

echo "You are not register User";
exit ();
}

}
else
{// I WOULD LIKE TO DISPALY ANOTHER HTML/PHP FILE

echo "Enter Password";
exit();
}

}
else
{
echo "Enter The valid User name and Password" ;
exit() ;
}

?>

Your best bet is to use include() for the html files.

eg;
if (!strcasecmp( "y", $myrow["flag"]) )
{
include("./authorized.html");
}