Hi! I have been able to capture the "NTCH" messages whenever the state of a specific control changes. For example, when I click the "CheckBox1" control, the NTCH message is intercepted. The order goes like _MUP, ChCl (my customized command message for the control) and then NTCH. When I spoke to my supervisor, he told me that the NTCH message was the notification message. I looked at the information in it and it consists of 6 attributes: when, source, be:value, be:sender, be:observe_orig_what, be:observe_change_what. We believe this may be the message we were looking for when need to look at a control changing its state. The thing is I would like to see whether any of these attributes contain the value "CheckBox1" which I can use for my analysis. I suspect the "CheckBox1" string might be in the sender or source attributes. How do I look at these attributes though? Source is of a B_POINTER_TYPE (void* i think) and sender is BMessenger. I cant just do a toString() style of code to these attributes and view their values, isnt it? Regards, Yash