Please tell me how can i change config.php writable?

Please tell me how I can make config.php writable and how I can change  "mysql_query(): supplied argument is not a valid MySQL-Link resource in /home/dbss/domains/dbss.kuheo.com/public_html/install/db_ctrl.php on line 185" ?<?php

if (eregi("db_ctrl.php",$_SERVER['PHP_SELF'])) {
    die();
}
/*
 sql_connect($host, $user, $password, $db)
 sql_logout($id)
 sql_query($query, $id)
 sql_num_rows($res)
 sql_fetch_row(&$res, $nr=0)
 sql_fetch_object(&$res, $nr=0)
 sql_free_result($res)
 
 $dbtype:"MySQL;mSQL;PostgreSQL;PostgreSQL_local;ODBC;ODBC_Adabas;Interbase;Sybase"; */

class ResultSet {
    var $result;
    var $total_rows;
    var $fetched_rows;

    function set_result( $res ) {
        $this->result = $res;
    }

    function get_result() {
        return $this->result;
    }

    function set_total_rows( $rows ) {
        $this->total_rows = $rows;
    }

    function get_total_rows() {
        return $this->total_rows;
    }

    function set_fetched_rows( $rows ) {
        $this->fetched_rows = $rows;
    }

    function get_fetched_rows() {
        return $this->fetched_rows;
    }

    function increment_fetched_rows() {
        $this->fetched_rows = $this->fetched_rows + 1;
    }
}

function sql_connect($host, $user, $password, $db)
{
global $dbtype;
switch ($dbtype) {

    case "MySQL":
        $dbi=@mysql_connect($host, $user, $password);
        if (!$dbi)
            return false;
        if (!mysql_select_db($db)) {
        return false;
        //mysql_query("CREATE DATABASE $db");
        //mysql_select_db($db);
        //include("includes/install.php");
        die();
    }
        return $dbi;
    break;

    case "mSQL":
         $dbi=msql_connect($host);
         if (!msql_select_db($db)) {
        msql_query("CREATE DATABASE $db");
        msql_select_db($db);
        include("includes/install.php");
        die();
         }
     return $dbi;
    break;;

    case "PostgreSQL":
         $dbi=@pg_connect("host=$host user=$user password=$password port=5432 dbname=$db");
         return $dbi;
    break;;

    case "PostgreSQL_local":
         $dbi=@pg_connect("user=$user password=$password dbname=$db");
         return $dbi;
    break;;

    case "ODBC":
         $dbi=@odbc_connect($db,$user,$password);
         return $dbi;
    break;;

    case "ODBC_Adabas":
         $dbi=@odbc_connect($host.":".$db,$user,$password);
     return $dbi;
    break;;

    case "Interbase":
         $dbi=@ibase_connect($host.":".$db,$user,$password);
         return $dbi;
    break;;

    case "Sybase":
        $dbi=@sybase_connect($host, $user, $password);
    if (!sybase_select_db($db,$dbi)) {
        sybase_query("CREATE DATABASE $db",$dbi);
            sybase_select_db($db,$dbi);
            include("includes/install.php");
        die();
    }
    return $dbi;
    break;;

    default:
    break;;
    }

}

function sql_logout($id)
{
global $dbtype;
switch ($dbtype) {

    case "MySQL":
        $dbi=@mysql_close($id);
        return $dbi;
    break;;

    case "mSQL":
         $dbi=@msql_close($id);
         return $dbi;
    break;;

    case "PostgreSQL":
    case "PostgreSQL_local":
         $dbi=@pg_close($id);
         return $dbi;
    break;;
 
    case "ODBC":
    case "ODBC_Adabas":
         $dbi=@odbc_close($id);
         return $dbi;  
    break;;

    case "Interbase":
         $dbi=@ibase_close($id);
         return $dbi;
    break;;

    case "Sybase":
        $dbi=@sybase_close($id);
        return $dbi;
    break;;

    default:
    break;;
    }
}

/*
 * sql_query($query, $id)
 * executes an SQL statement, returns a result identifier
 */

function sql_query($query, $id)
{

global $dbtype;
global $sql_debug;
$sql_debug = 0;
if($sql_debug) echo "SQL query: ".str_replace(",",", ",$query)."<BR>";
switch ($dbtype) {

    case "MySQL":
       // $res=@mysql_query($query, $id);
        if (!$res = mysql_query($query,$id)) {
            return false;
            //echo "error:".$query;exit();
        }
        return $res;
    break;;

    case "mSQL":
        $res=@msql_query($query, $id);
        return $res;
    break;;

    case "PostgreSQL":
    case "PostgreSQL_local":
    $res=pg_exec($id,$query);
    $result_set = new ResultSet;
    $result_set->set_result( $res );
    $result_set->set_total_rows( sql_num_rows( $result_set ) );
    $result_set->set_fetched_rows( 0 );
        return $result_set;
    break;;

    case "ODBC":
    case "ODBC_Adabas":
        $res=@odbc_exec($id,$query);
        return $res;
    break;;

    case "Interbase":
        $res=@ibase_query($id,$query);
        return $res;
    break;;

    case "Sybase":
        $res=@sybase_query($query, $id);
        return $res;
    break;;

    default:
    break;;

    }
}

/*
 * sql_num_rows($res)
 * given a result identifier, returns the number of affected rows
 */

function sql_num_rows($res)
{
global $dbtype;
switch ($dbtype) {
 
    case "MySQL":
        $rows=@mysql_num_rows($res);
        return $rows;
    break;;

    case "mSQL":  
        $rows=msql_num_rows($res);
        return $rows;
    break;;

    case "PostgreSQL":
    case "PostgreSQL_local":
        $rows=pg_numrows( $res->get_result() );
        return $rows;
    break;;
        
    case "ODBC":
    case "ODBC_Adabas":
        $rows=odbc_num_rows($res);
        return $rows;
    break;;
        
    case "Interbase":
    echo "<BR>Error! PHP dosen't support ibase_numrows!<BR>";
        return $rows;
    break;;

    case "Sybase":
        $rows=sybase_num_rows($res);
        return $rows;
    break;;

    default:
    break;;
    }
}

/*
 * sql_fetch_row(&$res,$row)
 * given a result identifier, returns an array with the resulting row
 * Needs also a row number for compatibility with PostgreSQL
 */

function sql_fetch_row(&$res, $nr=0)
{
global $dbtype,$q;
switch ($dbtype) {

    case "MySQL":
        $row = mysql_fetch_row($res);
        return $row;
    break;;

    case "mSQL":
        $row = msql_fetch_row($res);
        return $row;
    break;;

    case "PostgreSQL":
    case "PostgreSQL_local":
    if ( $res->get_total_rows() > $res->get_fetched_rows() ) {
        $row = pg_fetch_row($res->get_result(), $res->get_fetched_rows() );
        $res->increment_fetched_rows();
        return $row;
    } else {
        return false;
    }
    break;;

    case "ODBC":
    case "ODBC_Adabas":
        $row = array();
        $cols = odbc_fetch_into($res, $nr, $row);
        return $row;
    break;;

    case "Interbase":
        $row = ibase_fetch_row($res);
        return $row;
    break;;

    case "Sybase":
        $row = sybase_fetch_row($res);
        return $row;
    break;;

    default:
    break;;
    }
}

function sql_fetch_array(&$res, $nr=0)
{
global $dbtype;
switch ($dbtype) {
    case "MySQL":
        $row = mysql_fetch_array($res);
        return $row;
    break;;
    }
}

function sql_fetch_object(&$res, $nr=0)
{
global $dbtype;
switch ($dbtype)
    {
    case "MySQL":
        $row = mysql_fetch_object($res);
    if($row) return $row;
    else return false;
    break;;

    case "mSQL":
        $row = msql_fetch_object($res);
    if($row) return $row;
    else return false;
    break;;

    case "PostgreSQL":
    case "PostgreSQL_local":
    if( $res->get_total_rows() > $res->get_fetched_rows() ) {
        $row = pg_fetch_object( $res->get_result(), $res->get_fetched_rows() );
        $res->increment_fetched_rows();
        if($row) return $row;
        else return false;
    } else {
        return false;
    }
    break;;

    case "ODBC":
        $result = odbc_fetch_row($res, $nr);
    if(!$result) return false;
    $nf = odbc_num_fields($res); /* Field numbering starts at 1 */
        for($count=1; $count < $nf+1; $count++)
    {
            $field_name = odbc_field_name($res, $count);
            $field_value = odbc_result($res, $field_name);
            $row->$field_name = $field_value;
        }
        return $row;
    break;;

    case "ODBC_Adabas":
        $result = odbc_fetch_row($res, $nr);
    if(!$result) return false;

        $nf = count($result)+2; /* Field numbering starts at 1 */
    for($count=1; $count < $nf; $count++) {
        $field_name = odbc_field_name($res, $count);
        $field_value = odbc_result($res, $field_name);
        $row->$field_name = $field_value;
    }
        return $row;
    break;;

    case "Interbase":
        $orow = ibase_fetch_object($res);
    if($orow)
    {
        $arow=get_object_vars($orow);
        while(list($name,$key)=each($arow))
        {
        $name=strtolower($name);
        $row->$name=$key;
        }
            return $row;
    }else return false;
    break;;

    case "Sybase":
        $row = sybase_fetch_object($res);
        return $row;
    break;;

    }
}

/*** Function Free Result for function free the memory ***/
function sql_free_result($res) {
global $dbtype;
switch ($dbtype) {

    case "MySQL":
        $row = mysql_free_result($res);
        return $row;
    break;;

       case "mSQL":
        $row = msql_free_result($res);
        return $row;
    break;;

        case "PostgreSQL":
    case "PostgreSQL_local":
        $rows=pg_FreeResult( $res->get_result() );
        return $rows;
    break;;

    case "ODBC":
    case "ODBC_Adabas":
        $rows=odbc_free_result($res);
        return $rows;
    break;;

    case "Interbase":
    echo "<BR>Error! PHP dosen't support ibase_numrows!<BR>";
        return $rows;
    break;;

    case "Sybase":
        $rows=sybase_free_result($res);
        return $rows;
    break;;
    }
}

?>