text: function validate_admin() {
      var aid=sessionStorage.getItem("role");
      if(aid!=4)
          window.location="http://localhost:8080/Feedback_System_war_exploded/admin.html";
  }
  function validate_stud() {
      var sid=sessionStorage.getItem("role");
      if(sid!=1)
          window.location="http://localhost:8080/Feedback_System_war_exploded/index.html";
  }
  function validate_hod() {
      var sid=sessionStorage.getItem("role");
      if(sid!=3)
          window.location="http://localhost:8080/Feedback_System_war_exploded/hod.html";
  }
  function validate_teacher() {
      var sid=sessionStorage.getItem("role");
      if(sid!=2)
          window.location="http://localhost:8080/Feedback_System_war_exploded/teacher.html";
  }
  function logout() {
      sessionStorage.setItem("role","0");
      window.location="http://localhost:8080/Feedback_System_war_exploded/index.html";
  }
  function logout_stud() {
      sessionStorage.setItem("role","0");
      sessionStorage.setItem("studid","0");
      sessionStorage.setItem("roll","0");
      sessionStorage.setItem("sclass","0");
      sessionStorage.setItem("sdiv","0");
      sessionStorage.setItem("sname","0");
      window.location="http://localhost:8080/Feedback_System_war_exploded/";
  }
  function logout_admin() {
      sessionStorage.setItem("role","0");
      window.location="http://localhost:8080/Feedback_System_war_exploded/admin.html";
  }
  function logout_hod() {
      sessionStorage.setItem("role","0");
      window.location="http://localhost:8080/Feedback_System_war_exploded/hod.html";
  }
  function logout_teacher() {
      sessionStorage.setItem("role","0");
      window.location="http://localhost:8080/Feedback_System_war_exploded/teacher.html";
  }