diff --git a/ATM.cpp b/ATM.cpp
index 400fa35..24466d0 100644
--- a/ATM.cpp
+++ b/ATM.cpp
@@ -1,198 +1,214 @@
-#include<conio.h>
-#include<iostream>
-#include<string>
-using namespace std;
-
+#include <iostream>
+#include <string>
+#include <vector>
+#include <unistd.h>  // For Linux
+// #include <windows.h>  // Uncomment this line for Windows users and comment out 'unistd.h'
 
-class atm										// class atm 
-{
-private:										// private member varibles
-	long int account_No;
-	string name;
-	int PIN;
-	double balance;
-	string mobile_No;
-
-public:											// public member functions
-
-	// setData function is setting the Data into the private member variables
-	void setData(long int account_No_a, string name_a, int PIN_a, double balance_a, string mobile_No_a)
-	{
-		account_No = account_No_a;	 // assigning the formal arguments to the private member var's
-		name = name_a;
-		PIN = PIN_a;
-		balance = balance_a;
-		mobile_No = mobile_No_a;
-	}
-
-	//getAccountNo function is returning the user's account no.
-	long int getAccountNo()
-	{
-		return account_No;
-	}
-
-	//getName function is returning the user's Name
-	string getName()
-	{
-		return name;
-	}
-
-	//getPIN function is returning the user's PIN
-	int getPIN()
-	{
-		return PIN;
-	}
-
-	//getBalance is returning the user's Bank Balance
-	double getBalance()
-	{
-		return balance;
-	}
-
-	//getMobileNo is returning the user's Mobile No.
-	string getMobileNo()
-	{
-		return mobile_No;
-	}
-
-	//setMobile function is Updating the user mobile no
-	void setMobile(string mob_prev, string mob_new)
-	{
-		if (mob_prev == mobile_No)						// it will check old Mobile no
-		{
-			mobile_No = mob_new;						// and Update with new, if old matches
-			cout << endl << "Sucessfully Updated Mobile no.";
-			_getch();				//getch is to hold the screen untill user press any key 																			
-		}
-
-		else							// Does not update if old mobile no. does not matches
-		{
-			cout << endl << "Incorrect !!! Old Mobile no";
-			_getch();			  
-		}
-	}
-
-	//cashWithDraw function is used to withdraw money from ATM
-	void cashWithDraw(int amount_a)
-	{
-		if (amount_a > 0 && amount_a < balance)		// check entered amount validity
-		{
-			balance -= amount_a;		// balance = balance - amount_a
-			cout << endl << "Please Collect Your Cash";
-			cout << endl << "Available Balance :" << balance;
-			_getch();				
-		}
-
-		else
-		{
-			cout << endl << "Invalid Input or Insufficient Balance";
-			_getch();				
-		}
-	}
+using namespace std;
 
+class ATM {
+private:
+    long int account_No;
+    string name;
+    int PIN;
+    double balance;
+    string mobile_No;
+    vector<string> transactionHistory;
+    bool isLocked = false;
+    int pinAttempts = 0;
+
+public:
+    void setData(long int account_No_a, string name_a, int PIN_a, double balance_a, string mobile_No_a) {
+        account_No = account_No_a;
+        name = name_a;
+        PIN = PIN_a;
+        balance = balance_a;
+        mobile_No = mobile_No_a;
+    }
+
+    long int getAccountNo() { return account_No; }
+    string getName() { return name; }
+    int getPIN() { return PIN; }
+    double getBalance() { return balance; }
+    string getMobileNo() { return mobile_No; }
+    vector<string> getTransactionHistory() { return transactionHistory; }
+    bool getLockStatus() { return isLocked; }
+
+    void setMobile(string mob_prev, string mob_new) {
+        if (mob_prev == mobile_No) {
+            mobile_No = mob_new;
+            cout << endl << "Successfully Updated Mobile no.";
+            getchar();
+        } else {
+            cout << endl << "Incorrect Old Mobile no!";
+            getchar();
+        }
+    }
+
+    void cashWithDraw(int amount_a) {
+        if (amount_a > 0 && amount_a <= balance && amount_a <= 20000) {  // Added the withdrawal limit condition
+            balance -= amount_a;
+            string transaction = "Withdrew: " + to_string(amount_a);
+            transactionHistory.push_back(transaction);
+            cout << endl << "Please Collect Your Cash";
+            cout << endl << "Available Balance: " << balance;
+            getchar();
+        } else if (amount_a > 20000) {
+            cout << endl << "Withdrawal limit exceeded! You can only withdraw up to 20000.";
+            getchar();
+        } else {
+            cout << endl << "Invalid Input or Insufficient Balance";
+            getchar();
+        }
+    }
+
+    void lockAccount() {
+        isLocked = true;
+        cout << endl << "Your account has been locked due to multiple incorrect attempts." << endl;
+        getchar();
+    }
+
+    void trackPinAttempts() {
+        pinAttempts++;
+        if (pinAttempts >= 3) {
+            lockAccount();
+        }
+    }
+
+    void resetPinAttempts() {
+        pinAttempts = 0;
+    }
+
+    void unlockAccount() {
+        isLocked = false;
+        pinAttempts = 0;
+        cout << endl << "Your account has been unlocked. Please try again with correct details.";
+        getchar();
+    }
 };
 
-int main()
-{
-	int choice = 0, enterPIN;		//enterPIN and enterAccountNo. ---> user authentication
-	long int enterAccountNo;
-
-	system("cls");
-
-	// created User ( object )
-	atm user1;
-	// Set User Details ( into object )         ( Setting Default Data )
-	user1.setData(987654321, "Hardik", 1234, 50000, "9370054900");
-
-
-	do
-	{
-		system("cls");
-
-		cout << endl << "****Welcome to ATM*****" << endl;
-		cout << endl << "Enter Your Account No ";	  // asking user to enter account no
-		cin >> enterAccountNo;
-
-		cout << endl << "Enter PIN ";				 // asking user to enter PIN
-		cin >> enterPIN;
-
-
-
-		// check whether enter values matches with user details
-		if ((enterAccountNo == user1.getAccountNo()) && (enterPIN == user1.getPIN()))
-		{
-			do
-			{
-				int amount = 0;
-				string oldMobileNo, newMobileNo;
-
-				system("cls");
-			
-				cout << endl << "**** Welcome to ATM *****" << endl;
-				cout << endl << "Select Options ";
-				cout << endl << "1. Check Balance";
-				cout << endl << "2. Cash withdraw";
-				cout << endl << "3. Show User Details";
-				cout << endl << "4. Update Mobile no.";
-				cout << endl << "5. Exit" << endl;
-				cin >> choice;						
-
-				switch (choice)						// switch condition
-				{
-				case 1:							
-					cout << endl << "Your Bank balance is :" << user1.getBalance();
-					// getBalance is ... printing the users	bank balance
-					_getch();
-					break;
-
-
-				case 2:								
-					cout << endl << "Enter the amount :";
-					cin >> amount;
-					user1.cashWithDraw(amount);			// calling cashWithdraw function 
-														// passing the withdraw amount 
-					break;
-
-
-				case 3:								
-					cout << endl << "*** User Details are :- ";
-					cout << endl << "-> Account no :" << user1.getAccountNo();
-					cout << endl << "-> Name      :" << user1.getName();
-					cout << endl << "-> Balance   :" << user1.getBalance();
-					cout << endl << "-> Mobile No. :" << user1.getMobileNo();
-					// getting and printing user details
-					_getch();
-					break;
-
-
-				case 4:								 
-					cout << endl << "Enter Old Mobile No. ";
-					cin >> oldMobileNo;							// take old mobile no
-
-					cout << endl << "Enter New Mobile No. ";
-					cin >> newMobileNo;							// take new mobile no
-
-					user1.setMobile(oldMobileNo, newMobileNo);	// now set new mobile no
-					break;
-
-					
-				case 5:
-					exit(0);						// exit application
-
-				default:							// handle invalid user inputs
-					cout << endl << "Enter Valid Data !!!";
-				}
-
-			} while (1);				  // condition will always TRUE and loop is										capable of running infinite times
-		}
-
-		else
-		{
-			cout << endl << "User Details are Invalid !!! ";
-			_getch();
-		}
-	} while (1);						// condition will always TRUE and loop is										capable of running infinite times
-
-	return 0;
+int main() {
+    int choice = 0, enterPIN;
+    long int enterAccountNo;
+
+    system("clear");
+
+    ATM user1;
+    user1.setData(987654321, "Hardik", 1234, 50000, "9370054900");
+
+    do {
+        system("clear");
+
+        cout << endl << "****Welcome to ATM*****" << endl;
+        cout << endl << "Enter Your Account No: ";
+        cin >> enterAccountNo;
+
+        cout << endl << "Enter PIN: ";
+        cin >> enterPIN;
+
+        if ((enterAccountNo == user1.getAccountNo()) && (enterPIN == user1.getPIN())) {
+            user1.resetPinAttempts();
+
+            do {
+                int amount = 0;
+                string oldMobileNo, newMobileNo;
+
+                if (user1.getLockStatus()) {
+                    cout << "Account is locked. Please contact support." << endl;
+                    break;
+                }
+
+                system("clear");
+
+                cout << endl << "**** Welcome to ATM *****" << endl;
+                cout << endl << "Select an option: ";
+                cout << endl << "1. Check Balance";
+                cout << endl << "2. Cash Withdraw";
+                cout << endl << "3. Show User Details";
+                cout << endl << "4. Update Mobile No.";
+                cout << endl << "5. View Transaction History";
+                cout << endl << "6. Lock Account (for security purposes)";
+                cout << endl << "7. Exit" << endl;
+                cin >> choice;
+
+                switch (choice) {
+                    case 1:
+                        cout << endl << "Your Bank balance is: " << user1.getBalance();
+                        getchar();
+
+                    case 2:
+                        cout << endl << "Enter the amount: ";
+                        cin >> amount;
+                        user1.cashWithDraw(amount);
+                        break;
+
+                    case 3:
+                        cout << endl << "*** User Details are: ***";
+                        cout << endl << "-> Account No: " << user1.getAccountNo();
+                        cout << endl << "-> Name: " << user1.getName();
+                        cout << endl << "-> Balance: " << user1.getBalance();
+                        cout << endl << "-> Mobile No.: " << user1.getMobileNo();
+                        getchar();
+                        break;
+
+                    case 4:
+                        cout << endl << "Enter Old Mobile No.: ";
+                        cin >> oldMobileNo;
+                        cout << endl << "Enter New Mobile No.: ";
+                        cin >> newMobileNo;
+                        user1.setMobile(oldMobileNo, newMobileNo);
+                        break;
+
+                    case 5:
+                        {
+                            vector<string> transactions = user1.getTransactionHistory();
+                            cout << endl << "*** Transaction History ***";
+                            for (const string& transaction : transactions) {
+                                cout << endl << transaction;
+                            }
+                            getchar();
+                        }
+                        break;
+
+                    case 6:
+                        user1.lockAccount();
+                        break;
+
+                    case 7:
+                        exit(0);
+
+                    default:
+                        cout << endl << "Enter Valid Data !!!";
+                        break;
+                }
+
+            } while (true);
+
+        } else {
+            cout << endl << "User Details are Invalid !!! ";
+            user1.trackPinAttempts();
+
+            if (user1.getLockStatus()) {
+                char retryChoice;
+                cout << endl << "Would you like to try again? (y/n): ";
+                cin >> retryChoice;
+
+                if (retryChoice == 'y' || retryChoice == 'Y') {
+                    cout << "Please wait for 30 seconds before retrying..." << endl;
+
+                    // Wait for 30 seconds (using sleep function for Linux)
+                    sleep(30);  // Use Sleep(30000) on Windows instead
+                    user1.unlockAccount();
+                    continue;  // Restart the loop for a new login attempt
+                } else {
+                    cout << "Exiting. Please try again later.";
+                    break;  // Exit the program
+                }
+            }
+            getchar();
+        }
+
+    } while (true);
+
+    return 0;
 }
-
diff --git a/a.out b/a.out
new file mode 100755
index 0000000..e8e63df
Binary files /dev/null and b/a.out differ