diff --git a/intValidCheck.cpp b/intValidCheck.cpp
deleted file mode 100644
index 6a5e935..0000000
--- a/intValidCheck.cpp
+++ /dev/null
@@ -1,35 +0,0 @@
-/****************************************************************************************************
- * * Program name: CS162 Project1
- * * Author: Taekyoung Kim
- * * Date: 01/10/2019
- * * Description: This is intValidCheck.cpp file for CS162 project1.
- * * This function check users' input validation, so if the input is not integer, keeps asking users
- * * to input the correct input.
- ******************************************************************************************************/
-
-#include "intValidCheck.h"
-#include <iostream>
-
-int intValidCheck(int input) {
-
-    // Check type validation first using std::cin.fail()
-
-    if(std::cin.fail()) {
-
-        do {
-            //std::cout << "Input" << input << std::endl;
-            std::cout << "Wrong input! You need to input proper value!" << std::endl;
-
-            std::cin.clear();
-            std::cin.ignore(INT_MAX, '\n');
-
-            std::cout << "Please try again. Input here: " << std::endl;
-            std::cin >> input;
-
-        } while(std::cin.fail());
-    }
-    else {
-        return input;
-    }
-    return input;
-}
\ No newline at end of file
diff --git a/main.cpp b/main.cpp
index ef44c08..1821c48 100644
--- a/main.cpp
+++ b/main.cpp
@@ -8,31 +8,11 @@
 
 #include <iostream>
 #include <random>
+#include <climits>
+#include <string>
 #include "intValidCheck.h"
 #include "AntStep.h"
-
-
-//function positNumCheck checks if the input is positive number.
-int positNumCheck(int input){
-
-    if(input > 0) {
-        return input;
-    }
-    else {
-        do {
-            //std::cout << "Input" << input << std::endl;
-            std::cout << "Wrong input! You need to input positive integer!" << std::endl;
-
-            std::cin.clear();
-            std::cin.ignore(INT_MAX, '\n');
-
-            std::cout << "Please try again. Input here: " << std::endl;
-            std::cin >> input;
-
-        } while(input<=0);
-    }
-    return input;
-}
+#include "validCh.h"
 
 //function inValidOneorTwo check if the input is 1 or 2.
 int inValidOneOrTwo(int input) {
@@ -58,18 +38,18 @@ int inValidOneOrTwo(int input) {
 //Function to show users menus for choosing to quit or start and get user's choice.
 int chooseMenu1(){
 
-    int choice;
+    std::string option;
+    int menu;
 
     std::cout<<"Welcome to Langton's Ant simulation. Choose your option."<<std::endl;
     std::cout<<"1. Start Langton's Ant simulation"<<std::endl;
     std::cout<<"2. Quit the simulation"<<std::endl;
-    std::cin>>choice;
+    //std::cin>>choice;
+    std::getline(std::cin, option);
+    menu = validCh(option);
+    menu = inValidOneOrTwo(menu);
 
-    //Call input validation functions.
-    choice = intValidCheck(choice);
-    choice = inValidOneOrTwo(choice);
-
-    switch(choice){
+    switch(menu){
         case 1:
             std::cout<<"You chose 1. Start the simulation. Let's start!"<<std::endl;
             break;
@@ -77,10 +57,10 @@ int chooseMenu1(){
             std::cout<<"You chose 2. Quit the simulation. Good buy!"<<std::endl;
             break;
         default:
-            break;
+            std::cout<<"You didn't choose 1 or 2"<<std::endl;
     }
 
-    return choice;
+    return menu;
 }
 
 int main() {
@@ -92,33 +72,31 @@ int main() {
     choiceResult = chooseMenu1();
 
     if(choiceResult == 1) {
-        int widthRow =0, lengthCol=0, numOfStep=0, startRow, startCol, choiceForRanNum;
+        int lengthCol, widthRow, numOfStep, choiceForRanNum, startRow, startCol;
+        std::string length, width, steps, choice, userRow, userCol;
 
         do {
             //Ask user to input Board's Length and Width and call input validation function for two inputs.
-            std::cout << "\nPlease choose a board size, input positive integer number for length and width: "
-                      << std::endl;
-            std::cin >> lengthCol;
-            std::cin >> widthRow;
+            std::cin.clear();
+            std::cin.ignore(INT_MAX, '\n');
+            std::cout <<"Please choose a board size, input positive integer number for length: "<< std::endl;
+            std::getline(std::cin, length);
+            lengthCol = validCh(length);
 
-            lengthCol = intValidCheck(lengthCol);
-            widthRow = intValidCheck(widthRow);
-            lengthCol = positNumCheck(lengthCol);
-            widthRow = positNumCheck(widthRow);
+            std::cout <<"Input number for width with a positive integer number: "<< std::endl;
+            std::getline(std::cin, width);
+            widthRow = validCh(width)
 
             //Ask user to input the number of steps of ant and call input validation function.
-            std::cout << "How many steps do you want the ant goes? Please input positive integer number for steps: "<< std::endl;
-            std::cin >> numOfStep;
-            numOfStep = intValidCheck(numOfStep);
-            numOfStep = positNumCheck(numOfStep);
-
-            std::cout << "Do you want to choose a starting point for the ant or make it start at a random location?"<<
+            std::cout <<"How many steps do you want the ant goes? Please input positive integer number for steps: "<< std::endl;
+            std::getline(std::cin, steps);
+            numOfStep = validCh(steps);
+           
+            std::cout <<"Do you want to choose a starting point for the ant or make it start at a random location?"<<
                       "\nIf you want a random location, input number 1. Or, if you want to choose it by yourself input 2.: "
                       << std::endl;
-            std::cin >> choiceForRanNum;
-            //valid check for random choice
-            choiceForRanNum = intValidCheck(choiceForRanNum);
-            //one or check for random choice
+            std::getline(std::cin, choice);
+            choiceForRanNum =validCh(choice);
             choiceForRanNum = inValidOneOrTwo(choiceForRanNum);
 
             if (choiceForRanNum == 1) {
@@ -133,26 +111,27 @@ int main() {
             }
 
             else { // choiceForRanNum == 2
-                //Ask user to input the start point and then call the input validation function.
-                std::cout << "Please choose the start point, input starting Row and Column number: " << std::endl;
-                std::cin >> startRow;
-                std::cin >> startCol;
-                startRow = intValidCheck(startRow);
-                startCol = intValidCheck(startCol);
-
-                if (!((startRow >= 0 && startRow < widthRow) && (startCol >= 0 && startCol < lengthCol))) {
 
-                    while (!((startRow >= 0 && startRow < widthRow) && (startCol >= 0 && startCol < lengthCol))) {
-                        std::cout << "Wrong input! You need to input between the board size" << std::endl;
-
-                        std::cin.clear();
-                        std::cin.ignore(INT_MAX, '\n');
-
-                        std::cout << "Please try again. Input here: " << std::endl;
-                        std::cin >> startRow;
-                        std::cin >> startCol;
-                        startRow = intValidCheck(startRow);
-                        startCol = intValidCheck(startCol);
+                //Ask user to input the start point and then call the input validation function.
+                std::cout <<"Please choose a start point with positive numbers, input starting Row: " << std::endl;
+                std::getline(std::cin, userRow);
+                startRow = validCh(userRow)-1;
+               
+                std::cout <<"Input starting Column here: " << std::endl;                
+                std::getline(std::cin, userCol);
+                startCol =validCh(userCol)-1;              
+
+                if (!((startRow < widthRow) && (startCol < lengthCol))){
+
+                    while (!((startRow < widthRow) && (startCol < lengthCol))) {
+                        std::cout <<"Wrong input! You need to input between the board size!"<< std::endl;                 
+                        std::cout <<"Please try again. Input start Row: " << std::endl;                       
+                        std::getline(std::cin, userRow);
+                        startRow = validCh(userRow)-1;
+
+                        std::cout <<"Start Column number here: "<<std::endl;
+                        std::getline(std::cin, userCol);
+                        startCol =validCh(userCol)-1;
                     }
                 }
             }
diff --git a/validCh.cpp b/validCh.cpp
new file mode 100644
index 0000000..9f88421
--- /dev/null
+++ b/validCh.cpp
@@ -0,0 +1,39 @@
+/****************************************************************************************************
+* * Program name: CS162 Project1
+* * Author: Taekyoung Kim
+* * Date: 01/10/2019
+* * Description: This is validCh.cpp file for CS162 project1.
+* * This function check users' input validation using string stream.
+* * So, if the input is not valid, it keeps asking users to input the correct data.
+******************************************************************************************************/
+
+
+#include "validCh.h"
+#include <iostream>
+#include <string>
+#include <sstream>
+
+int validCh(std::string info) {
+
+
+    int num = 0;
+    bool cond = true;
+
+    while (true) {
+        //std::cout << "Enter num: " << std::endl;
+        //getline(std::cin, info);
+        std::stringstream sstr(info);
+        if (sstr >> num && num >0) {
+            break;
+        }
+
+        //std::cin.clear();
+        //std::cin.ignore(INT_MAX, '\n');
+        std::cout << "Invalid input! please try again" << std::endl;
+        getline(std::cin, info);
+
+
+    }
+
+    return num;
+}
diff --git a/intValidCheck.h b/validCh.h
similarity index 57%
rename from intValidCheck.h
rename to validCh.h
index 9feb2b0..ccfe458 100644
--- a/intValidCheck.h
+++ b/validCh.h
@@ -2,12 +2,13 @@
  * * Program name: CS162 Project1
  * * Author: Taekyoung Kim
  * * Date: 01/10/2019
- * * Description: This is intValidCheck.h header file of intValidCheck.cpp file for CS162 project1.
+ * * Description: This is validCh.h header file of intValidCheck.cpp file for CS162 project1.
  ***************************************************************************************************/
 
-#ifndef INTVALIDCHECK_H
-#define INTVALIDCHECK_H
+#ifndef VALIDCH_H
+#define VALIDCH_H
+#include <iostream>
 
-int intValidCheck(int input);
+int validCh(std::string input);
 
-#endif
\ No newline at end of file
+#endif //PROJECT1_1_VALIDCH_H