Get Summation Doing Checkbox Checked In Oracle Apex Via JavaScript

To Get Summation By Doing Checkbox Checked In Oracle Apex Via JavaScript.

Step 1. Create a CheckBox item and with Some  Numbers by Query or Static. Like :

     select 100,100 a from dual
     union
     select 200,200 a from dual
     union
     select 300,300 c from dual

Step 2. Create another item with  Textfield type to show summation result .

Step 3. Now Copy-Pest the function to

Page Properties  > Function and Global Variable Declaration 

/* P43_SUM = Textfield item ID where we show the result.
P43_NEW = Checkbox item from where we get value. 
P43_NEW_ = First portion of every Checkbox ID . */

 function findTotal() {
        var arr = document.getElementsByName('P43_NEW');
        var tot = 0;
        var count= 0 ;
    for (var i = 0; i<arr.length; i++) {  
        if ($('#P43_NEW_'+i).prop('checked') == true) {      
            count = count + 1 ;
            tot += parseInt(arr[i].value);
        document.getElementById('P43_SUM').value =  tot;
         }
         else  if (count == 0 ){
               document.getElementById('P43_SUM').value =  0;
         }         
      }
    } 

Step 4. Finally  Call the JavaScript Function Like.
Checkbox item properties > Advanced  > Custom Attributes

     onchange="findTotal();"

-------------------------------------Thank You----------------------------------