null

public/react/src/modules/courses/coursesPublic/Addcourses.js

@@ -89,6 +89,7 @@ class Addcourses extends Component{
       })
     }else{
       this.setState({
+        professor:null,
         assistant_professor:null,
         Checkboxteacherchecked:e.target.checked,
         Checkboxteachingtype:false