function Update($mysqli,$table_name, $form_data, $where_clause='',$v=0){   


  $whereSQL = '';


  if(!empty($where_clause)){


    // check to see if the 'where' keyword exists


    if(substr(strtoupper(trim($where_clause)), 0, 5) != 'WHERE'){


        // not found, add key word


      $whereSQL = " WHERE ".$where_clause;


    } else {


      $whereSQL = " ".trim($where_clause);


    }


  }


  // start the actual SQL statement


  $sql = "UPDATE `".$table_name."` SET ";


  // loop and build the column /


  $sets = array();


  foreach($form_data as $column => $value) {


    $sets[] = "`".$column."` = '".$value."'";


  }


  $sql .= implode(', ', $sets);


  // append the where statement


  $sql .= $whereSQL;


  // run and return the query result


  if($v==1) {


    echo $sql."<br>";


  }


  return mysqli_query($mysqli,$sql);


}