This one's usually really easy to fix. If there's an IF statement there, then it will probably look like this:
if (a==10);
although the contents of the brackets will be different. Note the semicolon after the statement. Remove that, and everything should be fine.
(test)
Another possibility is that you forgot to put in the curly brackets:
if (a==10) System.out.println("it is 10") b++ else System.out.println("it is not 10") c++
would become...
if (a==10) { System.out.println("it is 10") b++ } else { System.out.println("it is not 10") c++ }