Nikon Coolpix 5700 Digital Camera "d50 wont pic" Questions

...d50 is having trouble focusing sporadically regardless of setting.in auto mode it sometimes wont take a picture at all(it used to) but when i switch to manual then go back to auto it sometimes works. ...

...wont allow me to take a pic, can you please tell me how to or where to go to get the F off and continue taking pics. nikon D50 Have you changed the lens?. Most of the time the blinking F means that ...