Service Unavailable + Web AS 6.40

Hello Friends,

I have download and install sap web application 6.40 from sdn. I am creating an application. Things were going fine, I can create and deploy my application. few mins before, my system got hang, I close the server and restart the system. Now after restart I again start the server and deploy my application, it shows me the msg that my application successfully deployed, but when I try to access the application it shows me the following error msg !

503 Service Unavailable

Application stopped!

Details: You have requested an application that is currently stopped

I dont know what happend, I have not stopped any service???

Any idea what can be possibilly wronge ?

Many thanks,

Marek