Possible Duplicate:
Developing for Android in Eclipse: R.java not generating
what to do if R.Java file is delete when clean the project from eclipse ?
Possible Duplicate:
Developing for Android in Eclipse: R.java not generating
what to do if R.Java file is delete when clean the project from eclipse ?
It is normal that cleaning your project deletes the R.java file, this file is generated when your project is built.
If it's not generated when building it's generally because your resources files contains errors, check the problems view.
You should have checked the site for similar questions, though the common answer is, there's either a syntax error in your code (generally in a layout) or your android sdk is not installed properly.
Did you add in an external library such as the compatibility library? It can sometimes cause this problem, and there are a fair number of posts related to this, if it describes your situation. I'd search 'R removed compatibility library'.
You have a problem with the xml files, you must check them all and then(if you are using eclipse) go to: -proyect. -clean. -And then select your current proyect. It'll work.