Oracle 10g express not working in Ubuntu

After downloading Oracle 10g Express Edition for Linux (Ubuntu) I installed it in my Ubuntu 10.10 OS running computer successfully , but after installation I cannot open the “Database Home Page” but I installed the same version of this software of windows in windows in the same computer and now it is working nicely.

Now I want to know how to solve this problem of Oracle 10g express Edition of Ubuntu10.10
