Mine

$query_sjekk_muskel = "SELECT COUNT(*) FROM tp_muskel WHERE muskel='$muskel' AND muskeldel='$muskeldel'";
$result_sjekk_muskel = mysql_query($query_muskel,$conn);

if ($result_sjekk_muskel =='0') { 
$query_legginn_muskel = "insert into tp_muskel(id,muskel,muskeldel,nerve,entrapment) values ($tp_id,'$muskel','$muskeldel','$nerve','$entrapment')";
$result_legginn = mysql_query ($query_legginn_muskel, $conn);
}