How to insert values with a new type ?

Hi,

I have the following program :

#include <stdio.h>

typedef struct complexe {
float x;
float y;
} complexe;

complexe * complex_in(float x, float y)
{
complexe *result;

result = (complexe *)palloc(sizeof(complexe));
result->x = x;
result->y = y;

return (result);
}

char * complex_out(complexe *complex)
{
char *result;

if (complex == NULL)
return(NULL);
result = (char *) palloc(60);
sprintf(result, "(%f,%f)", complex->x, complex->y);

return(result);
}

(I took this from someone else...)

Now, I do these SQL commands :

CREATE FUNCTION complex_in(opaque)
RETURNS complex
AS '/ens/klimann/PostgreSQL/complexe.o'
LANGUAGE 'c';

CREATE FUNCTION complex_out(opaque)
RETURNS opaque
AS '/ens/klimann/PostgreSQL/complexe.o'
LANGUAGE 'c';

CREATE TYPE complex (
internallength = 16,
input = complex_in,
output = complex_out
);

CREATE TABLE nombres (
val COMPLEX
);

And I want to insert values in the table nombres.
I have tried this :
INSERT INTO nombres
VALUES (complex_in(1.0, 4.0));

and this :
INSERT INTO nombres
VALUES (1.0, 4.0);

and also this :
INSERT INTO nombres
VALUES ('1.0, 4.0');

and several other possibilities, but none seems to be right.

Has someone an idea ?

Thanks,
Ines.