[Squirrel-sql-users] Help with Informix needed

I am able to connect to my Informix database with following code:

    java.sql.Connection conn;

    Class.forName("com.informix.jdbc.IfxDriver");
    conn =
java.sql.DriverManager.getConnection("jdbc:informix-sqli://disko:1540/htracu
ni:INFORMIXSERVER=diskotcp;user=<user>;password=<password>");

Can someone explain me what I have to put in URL textbox of alias for my
connection. I have tried everything but
all I get is message box with java.lang.NullPointerException error

Thanks,
Igor