Qfyilyi

function PopulateEndDate() {

            var d2;

            var paymentDays;

            var stDate;

            var pDate;

        

            if (document.getElementById("startDate"))

                stDate = document.getElementById("startDate").value;

            if (document.getElementById("presentDate"))

                pDate = document.getElementById("presentDate").value;

                

                

            var futureSDate =  (pDate < stDate); //future start date

            var pastSDate = (pDate > stDate); //start date was in the past

            var sameDates = (pDate == stDate);

            

         

            

           

            if (stDate && futureSDate){

                d2 = new Date(stDate);

            }

            else if (stDate && sameDates){

                d2 = new Date(stDate);

            }

            else if (stDate && pastSDate){

                d2 = new Date(stDate);

                alert ("enter total number of payments");

            }

            else{

                d2 = new Date(pDate);

            }

            

            var dd = d2.getDate()+1000;

            var mm = d2.getMonth()+1;

            var yyyy = d2.getFullYear();

            var today = (mm+'/'+dd+'/'+yyyy);



           

             var paymentDays = document.getElementById("paymentRemaining").value;

              

            if (paymentDays && paymentDays != "")

            //   d2.setMonth(d2.getMonth() + parseInt(paymentDays));

            var n = d2.getDate();

            d2.setDate(1);

            d2.setMonth(d2.getMonth() + parseInt(paymentDays));

            d2.setDate(Math.min(n, getDaysInMonth(d2.getFullYear(), d2.getMonth())));

            if (document.getElementById("endDate"))

                document.getElementById("endDate").value = getCurrentDay(d2);

        }





  function isLeapYear(year) {

            return (((year % 4 === 0) && (year % 100 !== 0)) || (year % 400 === 0));

        }

        function getDaysInMonth(year, month) {

            return [31, (isLeapYear(year) ? 29 : 28), 31, 30, 31, 30, 31, 31, 30, 31, 30, 31][month];

        }

        

         function getCurrentDay(date) {

            var dateOfToday;

            if(date && date != "")

                dateOfToday = new Date(date);

            else dateOfToday = new Date();



            var dd = ("0" + (dateOfToday.getDate())).slice(-2);

            var mm = ("0" + (dateOfToday.getMonth() + 1)).slice(-2);

            var yyyy = dateOfToday.getFullYear();



            dateOfToday = yyyy + '-' + mm + '-' + dd;

            return dateOfToday;

        }

<label>Present Value as of date</label> <input id="presentDate" name="presentDate" onchange="PopulateEndDate()" type="date"><br/><br/>

<label>Start of Lease </label> <input  id="startDate" onchange="PopulateEndDate()"  type="date" >

<br/>

<br/>

<label>Remaining Payments</label> <input id="paymentRemaining" name = "paymentRemaining" onchange="PopulateEndDate()" type="number" class="label1" style="text-align: right; width:80px;"> <br/><br/>

<label>End of Lease</label>  <input id="endDate" onchange="PopulateRentPaymentDates()" type="date" > <br/><br/>

let btn = document.getElementById("test");



btn.addEventListener( "click", function(){

	if ( document.getElementById("popup") ) {

  	document.getElementById("popup").style.display = "block";

  }

});

#popup {

  display: none; 

  width: 300px;

  height: 50px;;

  margin: 0 auto;

  background-color: lightblue;

  border-radius: 15px;

  text-align: center;

}



#popupMessage {

  font-size: 30px;

}

<div id="popup">

   <p id="popupMessage"> Your Popup Message</p>

</div>



<button id="test"> Popup</button>

let condition = false;



let btn = document.getElementById("popupBtn");



btn.addEventListener("click", function(){

  //set some condition to true on button click

  condition = true;



  //if condition is true then add the popup

    if ( condition ) {

    //create container

    let popupContainer = document.createElement("DIV");

    //add popupContainer class to the container

    popupContainer.setAttribute("class", "popupContainer");



    //create popup text

    let popupText = document.createElement("P");

    popupText.setAttribute("class", "popupMessage");

    //add popup text

    popupText.appendChild( document.createTextNode("Your Popup Message") );



    //add the popupText to popupContainer

    popupContainer.appendChild( popupText );





    //add the popup above p element with id popupAboveThisElement

    if ( document.getElementById("popupAboveThisElement") ) {

      document.getElementById("popupAboveThisElement").parentNode.insertBefore( popupContainer, document.getElementById("popupAboveThisElement") );

    }

 }//end if condition true

});

.popupContainer {

  display: block; 

  width: 300px;

  height: 50px;;

  margin: 0 auto;

  background-color: lightblue;

  border-radius: 15px;

  text-align: center;

}



.popupMessage {

  font-size: 30px;

}

<h1> A title </h1>



<p> Lorem ipsum dolor sit amet, consectetur adipisicing elit. Ea, mollitia dolorem repellat tenetur, et eligendi, ipsam consequuntur debitis temporibus laboriosam ducimus harum fuga, quae ipsa.</p>



<p id="popupAboveThisElement"> Lorem ipsum dolor sit amet, consectetur adipisicing elit. Excepturi, quis, nihil modi fuga debitis error delectus itaque est illum velit in aliquam deserunt ipsum, non cupiditate, alias consectetur. Saepe, deleniti, aliquid. Fugiat sit, iste, tempore optio nam dolorum alias maxime quam numquam autem aspernatur porro beatae. Fugiat saepe doloremque facere!</p>



<button id="popupBtn"> Display Popup</button>