data inserted in mysql

<?php
$con=mysqli_connect("localhost","root","","myschool");
if (isset($_POST['submit']))
{
$name=$_POST['n1'];
$fname=$_POST['f1'];
$gen=$_POST['g1'];
$class=$_POST['cla'];
$cource="";
$lat=$_POST['lat'];
$longt=$_POST['longt'];

if(!empty($_POST['c1'])){

foreach($_POST['c1'] as $selected){
$cource.= $selected.",";
}
}
$sql="INSERT INTO school(s_name,F_name,Class,Gender,Cource,Lat,Longt)VALUES('$name','$fname','$gen','$class','$cource','$lat','$longt')";

$qu=mysqli_query($con,$sql);

if($qu)
{
echo "data inserted";
}

else
{
echo mysqli_error($con);
}
}

?>