applet

Hi,
I'm writing un applet for my application with postgres but it don't load (I
think) jdbc driver.
I add in .hotjava/properties jdbc.drivers=postgresql.Driver.

try{
resultsTextArea.setText("elaborazione in corso");

Class.forName("postgresql.Driver");

String url = "jdbc:postgres:tesi";
String usr = "andrea";
String pwd = "";

db = DriverManager.getConnection(url, usr, pwd);

st = db.createStatement();

....
....
}

It jump this try block.
What I can do?