eclipse 中每次修改js或者Java代碼後保存都會出現下面的錯誤：
Errors occurred during the build.
Errors running builder 'JavaScript Validator' on project 'school_course'.
org.eclipse.wst.jsdt.internal.compiler.ast.IfStatement cannot be cast to org.eclipse.wst.jsdt.internal.compiler.ast.AbstractVariableDeclaration
解決辦法：
在設置裏面輸入mark occ 就能看到js裏面有個選項，去掉Mark occurrences of the selected......選擇項即可
