diff --git a/szamrendszer.js b/szamrendszer.js
index 0e7827c..eba2ecb 100644
--- a/szamrendszer.js
+++ b/szamrendszer.js
@@ -1,20 +1,174 @@
-function convertNumber(num) {
-    if (isNaN(num)) {
-        return "Please enter a valid number.";
-    }
-
-    return {
-        binary: num.toString(2), 
-        decimal: num.toString(10),
-        hexadecimal: num.toString(16).toUpperCase() 
-    };
-}
-
-const number = 255;
-console.log(convertNumber(number));
-
-{
-    "binary"; "11111111",
-    "decimal"; "255",
-    "hexadecimal"; "FF"
-}
\ No newline at end of file
+$(document).ready(function(){
+	var inputNumber = 0;
+	var selectedOption = "";
+	var answer = 0;
+
+	$("#inputNumber").keyup(function(){
+		inputNumber = $(this).val();
+		setAnswer("");
+		activeDieactiveBtn();
+	})
+	$("#fromTo").change(function(){
+		selectedOption = $(this).val();
+		activeDieactiveBtn();
+	})
+	
+	
+	$("#convertBtn").click(function(){
+		if(selectedOption == "decimal to binary" && inputNumber != ""){
+			answer = convertDecimalToBinary(inputNumber);
+			setAnswer(answer);
+		}else if(selectedOption == "binary to decimal" && inputNumber != ""){
+			answer = convertBinaryToDecimal(inputNumber);
+			setAnswer(answer);
+		}else if(selectedOption == "decimal to hexadecimal" && inputNumber != ""){
+			answer = convertDecimalToHexadecimal(inputNumber);
+			setAnswer(answer);
+		}else if(selectedOption == "hexadecimal to decimal" && inputNumber != ""){
+			answer = convertHexadecimalToDecimal(inputNumber);
+			setAnswer(answer);
+		}else if(selectedOption == "binary to hexadecimal" && inputNumber != ""){
+			var decimalVal = convertBinaryToDecimal(inputNumber);
+			answer = convertDecimalToHexadecimal(decimalVal);
+			setAnswer(answer);
+		}else if(selectedOption == "hexadecimal to binary" && inputNumber != ""){
+			var decimalVal = convertHexadecimalToDecimal(inputNumber);
+			answer = convertDecimalToBinary(decimalVal);
+			setAnswer(answer);
+		}else{
+			resetAll();
+		}
+	})
+	
+	$("#resetBtn").click(function(){
+		resetAll();
+	})
+	
+})
+
+function activeDieactiveBtn(){
+	
+	var inputNumber = $("#inputNumber").val();
+	var selectedOption = $("#fromTo").val();
+	
+	if(inputNumber != "" && selectedOption != ""){
+		$("#convertBtn").prop("disabled",false);
+	}else{
+		$("#convertBtn").prop("disabled",true);
+	}
+	
+	if(inputNumber != "" || selectedOption != ""){
+		$("#resetBtn").prop("disabled",false);
+	}else{
+		$("#resetBtn").prop("disabled",true);
+	}
+	
+}
+
+function setAnswer(answer){
+	$("#showAnswer").html(answer);
+}
+
+function resetAll(){
+		$("#convertBtn").prop("disabled",true);
+		$("#showAnswer").html("");
+		$("#inputNumber").val("");
+		$("#fromTo").val("").change();
+		$(this).prop("disabled",true);
+}
+
+
+// main functions
+function convertDecimalToBinary(inputNumber){
+	var answer = "";
+	if(!isNaN(inputNumber)){
+		inputNumber = Number(inputNumber);
+		var remainder = 0;
+		while(inputNumber != 0){
+			remainder = inputNumber % 2;
+			inputNumber = ((inputNumber - remainder) / 2);
+			answer = remainder + answer;
+		}
+	}else{
+		answer = '<span style="color: red;">This is not decimal number!</span>';
+	}
+	return answer;
+}
+
+function convertBinaryToDecimal(inputNumber){
+	inputNumber = inputNumber.toString();
+	var numberLen = inputNumber.length;
+	var position = numberLen;
+	var answer = 0;
+	for(var i = 0; i < numberLen; i++){
+		if(inputNumber[i] == '0' || inputNumber[i] == '1'){
+			position--;
+			answer = answer + (   Number(inputNumber[i]) *  Math.pow(2, position) );
+		}else{
+			answer = '<span style="color: red;">This is not binary number!</span>';
+		}
+	}
+	return answer;
+}
+
+function convertDecimalToHexadecimal(inputNumber){
+	inputNumber = Number(inputNumber);
+	var remainder = 0;
+	var answer = "";
+	if(!isNaN(inputNumber)){
+			inputNumber = Number(inputNumber);
+			while(inputNumber != 0){
+			remainder = inputNumber % 16;
+			inputNumber = ((inputNumber - remainder) / 16);
+			if(remainder == 10){
+				answer = 'A' + answer;
+			}else if(remainder == 11){
+				answer = 'B' + answer;
+			}else if(remainder == 12){
+				answer = 'C' + answer;
+			}else if(remainder == 13){
+				answer = 'D' + answer;
+			}else if(remainder == 14){
+				answer = 'E' + answer;
+			}else if(remainder == 15){
+				answer = 'F' + answer;
+			}else{
+				answer =  remainder + answer;
+			}
+		}
+	}else{
+		answer = '<span style="color: red;">This is not decimal number!</span>';
+	}
+	return answer;
+}
+
+function convertHexadecimalToDecimal(inputNumber){
+	inputNumber = inputNumber.toString();
+	var numberLen = inputNumber.length;
+	var position = numberLen;
+	var answer = 0;
+	for(var i = 0; i < numberLen; i++){
+		var num = inputNumber[i];
+		if(num == 'A'){
+			num = 10;
+		}else if(num == 'B'){
+			num = 11;
+		}else if(num == 'C'){
+			num = 12;
+		}else if(num == 'D'){
+			num = 13;
+		}else if(num == 'E'){
+			num = 14;
+		}else if(num == 'F'){
+			num = 15;
+		}else if(num >= '0' && num <= '9'){
+			num = Number(num);
+		}else{
+			answer = '<span style="color: red;">This is not Hexadecimal number!</span>';
+			return answer;
+		}
+		position--; 
+		answer = answer + (num* Math.pow(16,position));
+	}
+	return answer;
+}   
\ No newline at end of file