Multiple table insert with php mysql

[chillininvt]

Ok I am having and issue getting this code working. It seems rather simple but I cannot figure out why only one sql statement is exectuing and the insert statements the other 2 are not exectuting and updating the other 2 tables. I need to do this. I need to update one table, then from that I need to retrieve the mysql_insert_id or just get the id of the last record in the tabe. There is an auto increment column that gets assigned a unique id each time a record is inserted. I need this id number then I need it to place data into 2 other tables that will use this value as a reference. here is the code.

if( isset($_POST['btnSubmit']) ) {
   $department_id = $_GET['department_id'];
   
   if( $department_id == "" ) {
      // ADD NEW
    mysql_query("INSERT INTO CityHallDepartment (department_name)
                   VALUES ('" . $_POST['department_name'] . "')");

echo "This is the department id".$departmentid."";
$departmentname = $_POST['department_name'];
if($departmentname != NULL){	
$departmentid = mysql_insert_id();
      mysql_query("INSERT INTO PageGeneric (pid, bannerid, title, content, metadesc, layoutID) VALUES ('0', '$departmentname', 'Comming Soon', '$departmentname', '3')");
   echo"The script executed into while loop";
	$page = "generalpage.php?page=".$departmentid."";
  mysql_query("INSERT INTO PageLocations (parentID, location, title, display, displayNavCMS, departmentID) VALUES ('0', '$page', '$departmentname', '1', '1', '0', $departmentid)");
 }else{