Prevent LinkButton post back OnClientClick not working. Why?

Question

I know there are plenty of answers surrounding this topic but I just cannot get this to work.

I need to prevent a link button posting back and the following code is not working. The code is definitely being hit in all the required places.

Link button definition:

  <asp:LinkButton ID="NavHelp" OnClientClick="showConfirm(event);" OnClick="NavHelp_Click" ToolTip="Help" runat="server"></asp:LinkButton>

Javascript function (definitely being hit)

function showConfirm(event) {
  event.stopPropagation();
  return false;
}

However after showConfirm returns false the link button still posts back to the server side NavHelp method.

As a side note, I also put a breakpoint in the __doPostback method generated by .NET and it does get hit after showConfirm returns false.

Can anyone shed any light on this?

Answer 1

Right, figured it out. I needed to include the return statement in the OnClientClick attribute:

OnClientClick="return showConfirm(event);"

NOT

OnClientClick="showConfirm(event);"