add problem 1 in javascript

javascript/001/problem_1.js

@@ -0,0 +1,12 @@
+/*
+If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.
+
+Find the sum of all the multiples of 3 or 5 below 1000.
+*/
+sum = 0;
+for (i = 1; i < 1000; i++ ) {
+    if (i % 3 == 0 || i % 5 == 0) {
+        sum += i;
+    }
+}
+console.log(sum)