Simple If and statment! Please help

[todayme]

I have this code below but I only want authentication to fail if both the number of rows are less than 1 AND if $SESSION['accountsession'] is equal to ""

 

Anyone got any sugestions I am very new to PHP so I am not firmiliar with syntax.  Thankyou in advance.

 

if(mysql_num_rows($data) < 1) and $SESSION['accountsession'] = ""

 

Is the above correct? I bet its not!  Please if someone could post there opinion.

 

session_start();

$_SESSION['accountsession'] = $accountsession;
   
if(mysql_num_rows($data) < 1)



	{
      			print "Authentication Failed";


							session_unset();
								session_destroy();

							print "Session Destroyed";


      					exit();
			}

[genericnumber1]

if(mysql_num_rows($data) < 1 && $SESSION['accountsession'] == "") {

[todayme]

Arrrrrrrr thanks heaps still geting use to new language.