BHO and IE ToolBar Button

Hi,

I am making an app which needs BHO. The BHO does its work perfectly. I
want to put a switch on IE to turn the BHO on or off. What is the best
way to do it? I tried adding Toolbar button in IE and tried to capture
the button click event but I couldn't get it working. I followed all
the steps described in
http://msdn.microsoft.com/library/default.asp?url=/workshop/browser/ext/tutorials/button.asp
but the call back method Exec doesn't gets fired when I click the
event. What is the possible reason? Can somebody help me please?

.