problems in compiling

Hello sir,

Whenever I compile the following sample code

# include <stdio.h>
# include <pgsql/libpq-fe.h>

void
exit_nicely(PGconn *conn)
{
PQfinish(conn);
exit(1);
}

main()
{
char *pghost,
*pgport,
*pgoptions,
*pgtty;
char *dbName;
int nFields;
int i,
j;

/* FILE *debug; */
.........

}

i get a compilation error which is of the following

/tmp/ccTCPDUs.o(.text+0x77): undefined reference to `PQstatus'
/tmp/ccTCPDUs.o(.text+0xa1): undefined reference to `PQerrorMessage'
/tmp/ccTCPDUs.o(.text+0xd4): undefined reference to `PQexec'
/tmp/ccTCPDUs.o(.text+0xeb): undefined reference to `PQresultStatus'
/tmp/ccTCPDUs.o(.text+0x118): undefined reference to `PQclear'
/tmp/ccTCPDUs.o(.text+0x130): undefined reference to `PQclear'
/tmp/ccTCPDUs.o(.text+0x141): undefined reference to `PQexec'
/tmp/ccTCPDUs.o(.text+0x158): undefined reference to `PQresultStatus'
/tmp/ccTCPDUs.o(.text+0x180): undefined reference to `PQclear'
/tmp/ccTCPDUs.o(.text+0x198): undefined reference to `PQclear'
/tmp/ccTCPDUs.o(.text+0x1a9): undefined reference to `PQexec'
/tmp/ccTCPDUs.o(.text+0x1c0): undefined reference to `PQresultStatus'
/tmp/ccTCPDUs.o(.text+0x1e8): undefined reference to `PQclear'
/tmp/ccTCPDUs.o(.text+0x200): undefined reference to `PQnfields'
/tmp/ccTCPDUs.o(.text+0x229): undefined reference to `PQfname'
/tmp/ccTCPDUs.o(.text+0x265): undefined reference to `PQntuples'
/tmp/ccTCPDUs.o(.text+0x29d): undefined reference to `PQgetvalue'
/tmp/ccTCPDUs.o(.text+0x2d7): undefined reference to `PQclear'
/tmp/ccTCPDUs.o(.text+0x2e8): undefined reference to `PQexec'
/tmp/ccTCPDUs.o(.text+0x2f9): undefined reference to `PQclear'
/tmp/ccTCPDUs.o(.text+0x30a): undefined reference to `PQexec'
/tmp/ccTCPDUs.o(.text+0x31b): undefined reference to `PQclear'
/tmp/ccTCPDUs.o(.text+0x327): undefined reference to `PQfinish'

what is the reason . i use the folowing command line cc file.c

thanks in advance

Mathew