checking unicode values with mysql_num_rows()

[Luodeni]

I made a function to check whether the first/middle/and lastname already exists in my database. It works just fine for latin names but it does not work on Chinese for example. My database has the value stored as unicode aswell and the characters represent the same I used (星星张 (xingxing Zhang)) as a name to check. Strangely enough it says this one doesn't exist yet, although it does. did anyone ever encountered this problem?

 

here is the function

 

<?php
function checkDuplicateContact( $firstName, $middleName, $lastName )
{
	$SQL = "SELECT customerid, firstname, middlename, lastname FROM tb_contacts
			WHERE firstname = '$firstName' AND middlename = '$middleName' AND lastname = '$lastName'
    		   ";

	$res = mysql_query( $SQL );

	if ( mysql_num_rows( $res ) == 1)
	{
		$error = "<div style='color: #D00;'>" . $_POST['firstname'] . " " . $_POST['middlename'] . " " . $_POST['lastname'] . ", already exists!</div>";
	}
	elseif ( mysql_num_rows( $res ) == 0 )
	{
		require 'includes/dbConnect.php';
		mysql_query("SET CHARACTER SET 'utf8'");
		mysql_query("SET NAMES 'utf8'");

		$SQLAdd = "INSERT INTO tb_contacts
				(
				 firstname, middlename, lastname, age, gender, dateofbirth, married, children, nationality, religion, companyid, jobtitle, 
				 jobdescription, officephone, homephone, mobilephone, mobilephone2, email, email2, instantmessenger, instantmessenger2,
				 fax, hobbies, favouritefood, favouritebeverage, miscelleneous, createdby, createddate
				)
				VALUES
				(
				 '$firstName', '$middleName', '$lastName', '$age', '$gender', '$dateofBirthFull', '$martialState', '$children', '$nationality',
				 '$religion', '$companyId', '$jobTitle', '$otherJobInfo', '$officePhone', '$housePhone', '$mobilePhone', '$mobilePhone2',
				 '$email', '$email2', '$instantMessenger', '$instantMessenger2', '$fax', '$hobbies', '$favouriteFood', '$favouriteBeverage',
				 '$miscelleneous', '$createdBy', CURRENT_TIMESTAMP()
				)
			   ";
			   
		$resAdd = mysql_query( $SQLAdd );

		mysql_close();

		$error = "<div style='color: #48830b'>" . $_POST['firstname'] . " " . $_POST['middlename'] . " " . $_POST['lastname'] . ", added to the database</div>";
		$_POST = "";
	}
	else 
	{
		$error = "<div style='color: #D00;'>" . mysql_error() . "Please contact the webadmin</div>"; 
	}
	return $error;
}
?>




<?php
				if ( isset( $_POST['firstname'] ) && $message != "")
				{
					echo "<div style='color: #D00;'>" . $message . "</div><br />\n";
				}
				elseif ( isset( $_POST['firstname'] ) && empty( $message) )
				{
					echo 	checkDuplicateContact( $firstName, $middleName, $lastName );
				}
?>