How to build a global error handling?

Hi,
how can i do that:
I want to have a global error page. For example ERROR.ASPX. When i now throw an error manually in my application like
catch (Exception e)
{
    throw new Exception ("My grain of salt", e) ;
}


And then the application should automatically jump to error.aspx and show the message "my grain of salt".


regards
yavuz
...