This depends if your doing it in c++ or C but truthfully it probably doesn't matter you should be able to do it with out a cast but it would give you a warning it really depends on what your doing with it. Ken _____ From: programmingblind-bounce@xxxxxxxxxxxxx [mailto:programmingblind-bounce@xxxxxxxxxxxxx] On Behalf Of Littlefield, Tyler Sent: Tuesday, December 11, 2007 5:27 AM To: programmingblind@xxxxxxxxxxxxx Subject: using lParam if it's a pointer Hello list, I've got a question. I'm using a callback function, and lParam contains a pointer to a struct of data. I'm using like lParam->bla=32; do I need to cast lParam to the struct first? (struct)lParam->bla=32; Thanks, Tyler Littlefield Vertigo head coder. "I can only please one person per day; Today doesn't seem like your day, and tomorrow doesn't look to promising either." "A life? Where can I download that at?" Contact information: email: tyler@xxxxxxxxxxxxx skype: st8amnd127 aim: st8amnd2005 msn: tyler@xxxxxxxxxxxxx