자바 배열을 이용한 아이디 저장 코드인데 출력이 잘 안됩니다.

public static void main(String[] args) { 
 
		//varaible declaration 
		int i,choice,lid,cid,f;
		String uid,chid,sid;  
		String l1[]=new String[5]; 
		String l2[]=new String[6]; 
		String l3[]=new String[5]; 
		String l4[]=new String[5]; 
 
 
	for(i=0;i<4;i++) { 
		l3[i]="empty"; 
			} 
	for(i=0;i<3;i++) { 
 
		l4[i]="empty"; 
		} 
		do 
		{ 
		f=0; //status of the machines 
			System.out.println("LAB STATUS"); 
			System.out.println("Lab # Computer Stations"); 
			System.out.print("1 "); 
 
			for(i=0;i<5;i++) { 
				System.out.print((i+1)+": "+l1[i]+" "); 
				} 
			System.out.println(); 
			System.out.print("2 "); 
			for(i=0;i<6;i++) 
			{ 
				System.out.print((i+1)+": "+l2[i]+" "); 
				} 
			System.out.println(); System.out.print("3 "); 
			for(i=0;i<4;i++) { 
				System.out.print((i+1)+": "+l3[i]+" "); 
				} 
			System.out.println(); System.out.print("4 "); 
			for(i=0;i<3;i++) {
				System.out.print((i+1)+": "+l4[i]+" "); 
				} 
			System.out.println(); 
			Scanner sc=new Scanner(System.in); 
			System.out.println("MAIN MENU"); 
			System.out.println("0) Quit"); 
			System.out.println("1) Simulate login"); 
			System.out.println("2) Simulate logoff"); 
			System.out.println("3) Search"); 
			choice = sc.nextInt();//asking for user choice 
			if(choice == 0) { 
				System.exit(0); 
			} 
			else if(choice == 1) { 
 
				//taking input from user 
				System.out.println("Enter the 5 digit ID number of the user logging in:"); 
				uid=sc.next(); System.out.println("Enter the lab number the user is logging in from (1-4):"); 
				cid=sc.nextInt(); System.out.println("Enter computer station number the user is logging in to (1-6):"); 
				cid=sc.nextInt(); 
				if(cid==1) { 
					l1[cid-1]=uid; 
					} 
 
				else 
					if(cid==2) { 
					l2[cid-1]=uid; 
					} 
				else 
					if(cid==3) { 
						l3[cid-1]=uid; 
						} 
					else 
						l4[cid-1]=uid; 
				} 
			else 
				if(choice == 2) { //taking input from user 
					System.out.println("Enter the 5 digit ID number of the user to find:"); 
					chid=sc.next(); 
					for(i=0;i<5;i++) { 
						if(l1[i].equalsIgnoreCase(chid)) l1[i]="empty"; 
						} 
					for(i=0;i<6;i++) { 
							if(l2[i].equalsIgnoreCase(chid)) l2[i]="empty"; 
							} 
						for(i=0;i<4;i++) { 
								if(l3[i].equalsIgnoreCase(chid)) l3[i]="empty"; 
								} 
						for(i=0;i<3;i++) { 
							if(l4[i].equalsIgnoreCase(chid)) l4[i]="empty"; 
							} 
						System.out.println("User "+chid+" is logged off."); 
						} else 
							if(choice == 3) { //taking input from user 
								System.out.println("Enter the 5 digit ID number of the user to find:"); 
								sid=sc.next(); 
								for(i=0;i<5;i++) { 
 
									if(l1[i].equalsIgnoreCase(sid)) { 
 
										System.out.println("User "+sid+" logged in lab 1 in system "+(i+1)); f=1; break; 
										}
									} 
								for(i=0;i<6;i++) { 
										if(l2[i].equalsIgnoreCase(sid)) { 
											System.out.println("User "+sid+" logged in lab 2 in system "+(i+1)); 
										f=1; break; 
										} 
									} 
									for(i=0;i<4;i++) { if(l3[i].equalsIgnoreCase(sid)) { 
										System.out.println("User "+sid+" logged in lab 3 in system "+(i+1)); 
										f=1; break; 
										} 
									} for(i=0;i<3;i++) { 
										if(l4[i].equalsIgnoreCase(sid)) { 
											System.out.println("User "+sid+" logged in lab 4 in system "+(i+1)); 
											f=1; break; 
											} 
										} 
									if(f==0) { 
										System.out.println("None of the user Id is not logged into any computer station"); 
										f=0; 
										} 
									} 
			}
		while(choice!=0); 
		} 
}