Iphone 4 lagging and home button occasionly not working

Im new to the forums here and my iphone is having issues. I have noticed my iphone 4 has been really laggy lately. Ive had it for a year and a half. At times to the home button does not work but other times the home button works great. It makes it hard to use the multiTouch gestures. On top of that as im

Typeing this on my iphone its lagging. Ive dleted my cache and history and all that. Ive cleaned out my notees, photos and apps but still nothing any suggestions?