function lecturechange(id){
			if(id==1){
				
				document.getElementById('lecturesh').style.display="block";
				document.getElementById('lecturebj').style.display="none";
				document.getElementById('lecturenj').style.display="none";
				document.getElementById('lectureshenzheng').style.display="none";
				document.getElementById('lecturewuhan').style.display="none";
				document.getElementById('lectureqindao').style.display="none";
				document.getElementById('lecturedalian').style.display="none";
				document.getElementById('lecturechangsha').style.display="none";
			}
			else if(id==2){
				
				document.getElementById('lecturesh').style.display="none";
				document.getElementById('lecturebj').style.display="block";
				document.getElementById('lecturenj').style.display="none";
				document.getElementById('lectureshenzheng').style.display="none";
				document.getElementById('lecturewuhan').style.display="none";
				document.getElementById('lectureqindao').style.display="none";
				document.getElementById('lecturedalian').style.display="none";
				document.getElementById('lecturechangsha').style.display="none";
			}
			else if(id==3){
				
				document.getElementById('lecturesh').style.display="none";
				document.getElementById('lecturebj').style.display="none";
				document.getElementById('lecturenj').style.display="block";
				document.getElementById('lectureshenzheng').style.display="none";
				document.getElementById('lecturewuhan').style.display="none";
				document.getElementById('lectureqindao').style.display="none";
				document.getElementById('lecturedalian').style.display="none";
				document.getElementById('lecturechangsha').style.display="none";
			}
			else if(id==4){
				
				document.getElementById('lecturesh').style.display="none";
				document.getElementById('lecturebj').style.display="none";
				document.getElementById('lecturenj').style.display="none";
				document.getElementById('lectureshenzheng').style.display="block";
				document.getElementById('lecturewuhan').style.display="none";
				document.getElementById('lectureqindao').style.display="none";
				document.getElementById('lecturedalian').style.display="none";
				document.getElementById('lecturechangsha').style.display="none";
			}
			else if(id==5){
				
				document.getElementById('lecturesh').style.display="none";
				document.getElementById('lecturebj').style.display="none";
				document.getElementById('lecturenj').style.display="none";
				document.getElementById('lectureshenzheng').style.display="none";
				document.getElementById('lecturewuhan').style.display="block";
				document.getElementById('lectureqindao').style.display="none";
				document.getElementById('lecturedalian').style.display="none";
				document.getElementById('lecturechangsha').style.display="none";
			}
			else if(id==6){
				
				document.getElementById('lecturesh').style.display="none";
				document.getElementById('lecturebj').style.display="none";
				document.getElementById('lecturenj').style.display="none";
				document.getElementById('lectureshenzheng').style.display="none";
				document.getElementById('lecturewuhan').style.display="none";
				document.getElementById('lectureqindao').style.display="block";
				document.getElementById('lecturedalian').style.display="none";
				document.getElementById('lecturechangsha').style.display="none";
			}
			else if(id==7){
				
				document.getElementById('lecturesh').style.display="none";
				document.getElementById('lecturebj').style.display="none";
				document.getElementById('lecturenj').style.display="none";
				document.getElementById('lectureshenzheng').style.display="none";
				document.getElementById('lecturewuhan').style.display="none";
				document.getElementById('lectureqindao').style.display="none";
				document.getElementById('lecturedalian').style.display="block";
				document.getElementById('lecturechangsha').style.display="none";
			}
			else if(id==8){
				
				document.getElementById('lecturesh').style.display="none";
				document.getElementById('lecturebj').style.display="none";
				document.getElementById('lecturenj').style.display="none";
				document.getElementById('lectureshenzheng').style.display="none";
				document.getElementById('lecturewuhan').style.display="none";
				document.getElementById('lectureqindao').style.display="none";
				document.getElementById('lecturedalian').style.display="none";
				document.getElementById('lecturechangsha').style.display="block";
			}
		}