billing.php

<?phprequire_once 'conc.php';
if ( !empty( $policeid ) ) {
    if ( isset( $_POST['police'] ) ) {
        $policeid = $_POST['police'];
    }
}
// Check connection
if ( mysqli_connect_errno() )
 {
    echo 'Failed to connect to MySQL: ' . mysqli_connect_error();
}
if ( !empty( $policeid ) ) {
    # code...
    $sql = "SELECT * FROM `billing` WHERE `police `=`$policeid`";
}
if ( !empty( $result ) ) {
    if ( $result = mysqli_query( $con, $sql ) )
    {
        $emparray = array();
        while( $row = mysqli_fetch_assoc( $result ) )
        $emparray[] = $row;

        echo( json_encode( $emparray ) );

        // Free result set
        mysqli_free_result( $result );
    }
}
mysqli_close( $con );
?>