The script was fine for an Access database but when I changed it over for a MySQL database the insertion queries sometimes (most of the time but not all the time) adds two records to the database.

Heres my connection:

$db_hostname   = "jd";
$db_username   = "john";
$db_password   = "nirvana";
$db_database   = "neuquote";

$conn = mysql_connect($db_hostname, $db_username, $db_password)
  or die ('Unable to connect to database');
		
$db = mysql_select_db($db_database,$conn)
  or die ('Unable to connect to database');

Heres my queries:

$today = getdate();
$today = $today['mday']."/".$today['mon']."/".$today['year']." ".$today['hours'].":".$today['minutes'].":".$today['seconds'];
						
// Insert new company
$sql="INSERT INTO Company (CompanyName,CompanyAddress1,CompanyAddress2,CompanyAddress3,CompanyAddress4,CompanyArea,CompanyCountryId,CompanyPostalCode,CompanyTel,CompanyFax,CompanyEmail,CompanyURL,CompanyDesc,CompanyStatus,TimeCompanyCreated) ". 
				 "VALUES ('$company_name','$company_address1','$company_address2','$company_address3','$company_address4','$company_area',$company_country,'$company_postal_code','$company_tel','$company_fax','$company_email','$company_url','$company_desc',0,'$today')";

$res_insert_company = mysql_query($sql,$conn);

//create a new hash to insert into the db and the confirmation email
$hash=md5($email.$hidden_hash_var);
$sql="INSERT INTO CompanyContact (ContactTitle,ContactFirstName,ContactSurname,ContactMiddleInitial,ContactAddress1,ContactAddress2,ContactAddress3,ContactAddress4,ContactArea,ContactCountryId,ContactPostalCode,ContactTel,ContactExt,ContactFax,ContactEmail,ContactPositionId,ContactUsername,ContactPassword,ContactRemoteAddress,ContactConfirmHash,ContactStatus,TimeContactCreated,CompanyId) ". 
					"VALUES ($title,'$first_name','$surname','$middle_initial','$address1','$address2','$address3','$address4','$area',$country_code,'$postal_code','$tel','$ext','$fax','$email',$pos,'$user_name','". md5($password1) ."','$GLOBALS[REMOTE_ADDR]','$hash',0,'$today',$company_id)";

$res_insert_contact=mysql_query($sql,$conn);

Most of the time two companies are added to the db and sometimes two companycontacts, this is not consistent though as sometimes it works fine.

I have checked the submit button is not being clicked twice and the code is running one insert for company and one for companycontact.

Is this a common problem with MySQL and PHP?