title: in a sample project R.java cannot be resolved to a variable
body: <p>I simply tried to import a sample project in the project workspace of Eclipse but without even touching the code, it gives huge number of errors all telling that R.java cannot be converted to a variable. But the file R.java is not present at all in the tree structure and I don't know that where it has gone. Now when I am creating a new Android project, it again gives the same error in that new project as well. I face this problem too often and it is a great hurdle for me..</p>
  
  <p>Can anybody please tell the cause and the solution to the problem?
  Thanks in advance.</p>