multitasking and return to application

on iphone with multitasking and iOS 4.x i run my app it work properly, now if i hit the home button (send a sms) and then double click the home button to return to my app i've notice that the app run like the first time not continue where i left it what is the solution to return to the point where you click the home button.

thanks开发者_如何转开发

You might want to make sure you're implementing the multitasking app delegate callbacks- check out the protocol reference: http://developer.apple.com/library/ios/#documentation/uikit/reference/UIApplicationDelegate_Protocol/Reference/Reference.html.