Assistance needed to modify my code for mysqli

Please can someone assist me to modify the below code to work with to interact with database. I have tried many options, but I keep getting either parameter warnings or errors. The following is my code:

$data['cid']=null;

function db_connect(){
    global $data;
    $data['cid']=@mysqli_connect(
        $data['Hostname'], $data['Username'], $data['Password']
    );
    if(!$data['cid'])echo('<font color=#FF0000>'.mysqli_error().'</font>');
    @mysqli_select_db($data['Database'], $data['cid']);
    return (bool)$data['cid'];
}

function db_disconnect(){
    global $data;
    return (bool)@mysqli_close($data['cid']);
}

function db_query($statement){
    global $data;
    return @mysqli_query($statement, $data['cid']);
}

function newid(){
    global $data;
    return @mysqli_insert_id($data['cid']);
}

function db_count($result){
    return (int)@mysqli_num_rows($result);
}

function db_rows($statement){
    $result=array();
    $query=db_query($statement);
    $count=db_count($query);
    for($i=0; $i<$count; $i++){
        $record=@mysqli_fetch_array($query, MYSQLI_ASSOC);
        foreach($record as $key=>$value)$result[$i][$key]=$value;
    }
    return $result;
}

Please let someone with good knowledge of mysqli help me out.