/notice is an IRC command that works pretty much like /msg (except it doesn't open a query window on the other end), so it's better not to confuse it with the local /echo which is used to print text to the screen.
Is there an identifier to merely tell whether a particular dialog window is open?
I recommend this alias that will activate an existing dialog instead of attempting to reopen it (paste into the remote and use /dlg lilmp3):
alias dlg dialog $iif($dialog($1),-v,-m) $1 $1 
