OCI Execute Error

[Delboy14]

I am having problems adding records to my database, the insert statement seems to work ok, but I have an error when the execute command is reached.

does anyone know where my problem is?

<?php
//try first to connect to the database. if we can't then end

$dbh = db_connect($database_user,$database_password,$database_name);
$stmt = OCIparse($dbh,&quot;insert into TRAVEL_REQUEST values(request_id_sequence.nextval,$dbdirid,'$origin', '$destination' ,
to_date($depart_date,'DD-MM-YYYY:hh24:mi:ss'),to_date($return_date,'DD-MM-YYYY:hh24:mi:ss'), '$purpose', '$justification',
'$approval_status')&quot;

if($stmt==false)
{
echo OCIError($stmt).&quot;<br>&quot;;
echo &quot;error in insert&quot;;
exit;
}

$execute=OCIexecute($stmt,OCI_DEFAULT);
ocicommit($dbh);

if($execute==false)
{
echo OCIError($execute).&quot;<br>&quot;;
echo &quot;error in execute&quot;;
exit;
}
OCIlogoff($dbh);
?>