Issues adding CONSTRAINT FOREIGN KEY in PhpMyAdmin - mysql

Question

I am trying to create 5 tables (should not be too hard), but I am having issues assigning the foreign keys. PhpMyAdmin gives me this error:
Can't create table 'databasexx.gave' (errno: 150)
Basically all the tables with no foreign keys are created.
DROP TABLE IF EXISTS oppbygging;
CREATE TABLE oppbygging (
gnr INT,
dnr INT,
ant INT,
CONSTRAINT dnr_grn_pk PRIMARY KEY (gnr, dnr)
) ENGINE=InnoDB;
DROP TABLE IF EXISTS onske;
CREATE TABLE onske (
onr INT,
pnr INT,
gnr INT,
prioriet INT,
ferdig INT,
CONSTRAINT pnr_gnr_pk PRIMARY KEY (pnr, gnr)
) ENGINE=InnoDB;
DROP TABLE IF EXISTS person;
CREATE TABLE person (
pnr INT,
fornavn VARCHAR(64),
etternavn VARCHAR(64),
fdato DATE,
CONSTRAINT pnr_pk PRIMARY KEY (pnr),
CONSTRAINT person_pnr_fk FOREIGN KEY (pnr) REFERENCES onske(pnr)
) ENGINE=InnoDB;
DROP TABLE IF EXISTS gave;
CREATE TABLE gave
(
gnr int,
navn varchar (255) UNIQUE,
prod_tid int NOT NULL,
CONSTRAINT gnr_pk PRIMARY KEY (gnr),
CONSTRAINT gave_gnr_fk FOREIGN KEY (gnr) REFERENCES oppbygging(gnr),
CONSTRAINT gave_gnr_fk FOREIGN KEY (gnr) REFERENCES onske(gnr)
) ENGINE=InnoDB;
DROP TABLE IF EXISTS del;
CREATE TABLE del (
dnr INT,
navn VARCHAR(64),
lager_ant INT NOT NULL,
CONSTRAINT dnr_pk PRIMARY KEY (dnr),
CONSTRAINT del_dnr_fk FOREIGN KEY (dnr) REFERENCES oppbygging(dnr)
) ENGINE=InnoDB;
I am sure that I am making some sort of obvious mistake, but I just cannot figure it out. Any help would be very much appreciated.
Here is the relationship view, ignore the Eiendom table:

Answer 1

TO CREATE ANOTHER TABLE WITH A FOREIGN KEY, THE FOREIGN KEY
SPECIFIED MUST BE THE PRIMARY KEY OF AT LEAST ONE TABLE
THAT HAS ALREADY BEEN CREATED,E.G.
CREATE TABLE 1 WITH THE PRIMARY KEY:
CREATE TABLE PERSONS(
PERSON_ID INT(10),
FNAME VARCHAR(20)NOT NULL,
LNAME VARCHAR(20),
DOB DATETIME,
AMOUNTPAID DECIMAL(15,2),
PRIMARY KEY(PERSON_ID)
);
THEN CREATE TABLE 2 WITH THE FOREIGN KEY:
CREATE TABLE COMMENTS(
COMMENTID INT AUTO_INCREMENT,
COMMENTS VARCHAR(500),
PERSON_ID INT(10),
PRIMARY KEY(COMMENTID),
FOREIGN KEY (PERSON_ID) REFERENCES PERSONS(PERSON_ID)
);