Prepared Statement Insert Problem

Hello everyone, I have a problem. I use the following to *try* and insert data into my MySQL database... //Variables come from a form $username= $_POST['username']; $password = $_POST['password']; $email = $_POST['email']; //Connect to the database $connect = mysqli_connect("$hostname", "$dbusername", "$dbpassword", "$database")or die("cannot connect"); //Find out how many rows in the database $aidcount = mysqli_query ($connect, "SELECT * FROM administrator"); $numrows = mysqli_num_rows($aidcount); //The next 3 lines are using prepared statements to insert data but the //second line ...mysqli_stmt_bind_param.. results in this error... //Fatal error: Only variables can be passed by reference in file.php line 46 $submitadmin = mysqli_prepare($connect2, "INSERT INTO administrator VALUES (?, ?, ?, ?)"); mysqli_stmt_bind_param($submitadmin, "isss", '$numrows', '$admin', sha1('$password'), '$email'); mysqli_stmt_execute($submitadmin); ...anyone know how I can solve this problem so I can insert data into my database with prepared statements?