abhgupta ,
Sorry that you are running into this issue with MyEclipse.
1) What kind of a project is it? Is it a simple Java project or a Web project ?
2) On which server are you deploying this project?
3) Here are a few things to check :
1. Window > Prefs > Java > Installed JREs. Make sure the JREs listed there are all valid.
2. Under your run configuraitons (Run As> Run Configurations) make sure the settings under JRE for your example are right.
4) Can you take a look at this thread and check if this fixes your issue ? : http://eclipsecoding.wikidot.com/faq#launchError
Let me know how this works for you.