javascript - Checking for NaN condition not working -

on page_load using 1 js function. default showing me nan have added condition checking nan below

var totalpaid = document.getelementbyid('txttotalpaid').value;         var totlandval = 0;          totlandval = parseint(expense) + parseint(totalpaid)          if (totlandval == 0 || totlandval == nan) {              document.getelementbyid('txttotallandval').value = 0;         }         else {             document.getelementbyid('txttotallandval').value = totlandval;         } 

but value still coming nan in textbox

use isnan() instead, because surprise:

nan == nan  // false