acomodame

 <?php
	 if($filter = (isset($_GET['nik']) ? strtolower($_GET['nik']) : NULL)){
		$sql = mysqli_query($conexion, "SELECT * FROM control WHERE idusuario='$filter' ORDER BY id ASC");		
	 }
	 if(mysqli_num_rows($sql) == 0){
			echo '<tr><td colspan="8">No hay datos.</td></tr>';
	  }else{
 ?>	
	 <select name="apart">
	 <?php           
		while($row = mysqli_fetch_assoc($sql)){ 
		   $sql_aparts_usuario = "SELECT * FROM aparts WHERE aparts_id='".$row['aparts_id']."'";  			
		   $rs_aparts_usuario = mysqli_query($conexion,$sql_aparts_usuario);
		   while($row2 = mysqli_fetch_assoc($rs_aparts_usuario)) 
		   {	
			 echo '<option value='.$row2['aparts_id'].'>'.$row2['apart'].'</option>';
			}                                       
		}               
	   ?>	                        
	  </select>  
 <?php    
	}                
?>