Problem with Custom Error Handler

Please refer my previous post here. I did changes accordingly but getting error. Please help me figure out the errors in this code. My IDE (Aptana) is giving red underlines on many lines of this code:

<?php

/* Include dependency */
require_once("./Config/dbconfig.php");

abstract class dbconnection 
{
    var $conn;
    try
    {
        //Opens connection for a MySQL DB
        public function OpenConnection()
        {
            $conn = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD) 
                or die (throw new DB_Exception_Handler('Cannot connect to DB: ' . $thisException->getMessage() . '.'));
            mysql_select_db(DB_NAME) or 
            die (throw new DB_Exception_Handler('Cannot connect to DB: ' . $thisException->getMessage() . '.')开发者_运维知识库);

        }

        //Closes connection for a MySQL DB
        public function CloseConnection()
        {
            mysql_close($conn);

        }
    }
    catch(DB_Exception_Handler($thisException)
    {
        $thisException->ShowError();
    }
}

class DB_Exception_Handler extends Exception
{
    public function ShowError()
    {
        echo "<script>alert('". $this->getMessage() ."');</script>"; 
    }   
}
?>

Things I notice is a try catch block within your class but not inside a method. and throwing a new exception from within a function call which is expecting either a string or an int (die()).

If you use the @ symbol you surpress error messages, both database functions return false if they fail.

Also you are calling a function on a reference $thisException that doesn't exist in the current scope it seems. But this might be because not all your code is here.

<?php

/* Include dependency */
require_once("./Config/dbconfig.php");

abstract class dbconnection {
    var $conn;

        //Opens connection for a MySQL DB
        public function OpenConnection() {
            $conn = @mysql_connect(DB_HOST, DB_USER, DB_PASSWORD); 
            if(!$conn) {
                throw new DB_Exception_Handler('Cannot connect to DB: ' . mysql_error() . '.');
            }
            if(mysql_select_db(DB_NAME) == false) {
                throw new DB_Exception_Handler('Cannot connect to DB: ' . mysql_error() . '.');
            }

        }

        //Closes connection for a MySQL DB
        public function CloseConnection()
        {
                mysql_close($conn);

        }

}

class DB_Exception_Handler extends Exception
{
    public function ShowError()
    {
        echo "<script>alert('". $this->getMessage() ."');</script>"; 
    }   
}
?>