Issue with preventing postback from client side (RadComboBox SelectedIndexChanged event)

I was doing some validation with a button on client side and if it failed, wanted to prevent from postback. This worked fine with button and client side event, by something like,

Approve

Here, WarningForIncreasingLimit() fires a confirmation dialog box and if the result is cancel, we return “false” hence preventing postback.
Here is the body,

function WarningForIncreasingLimit() {
               if (/*some calculation logic here*/) {
                   result = confirm("Some confirmation message, are you sure you want to continue?");
               }
               else {
                   result = true;
               }
       }

But it does not work when you use a RadComboBox with OnClientSelectedIndexChanged event.
I had a client event like

function radCmbMoveToClientChaneged(sender, eventArgs) {
           if (successful logic here)
               return true;
           else {
               var result = WarningForIncreasingLimit();
               return result;
           }
       }

Even if WarningForIncreasingLimit() above returns false, the method won’t prevent postback.
After some r&d , I figured that you have to the changing event instead on changed and set proper in set_cancel method like this.

function radCmbMoveToClientChanging(sender, eventArgs) {
           if (successful logic here)
               return true;
           else {
               var result = WarningForIncreasingLimit();

               if (!result) {
                   eventarqs.set_cancel(true);
               }

               return result;
           }
       }