Solving 2 problem in Activity.java Android

Hello Friends I try to write some codes but i could not do completely I wanted. 1- I have a asynctask function . I want that this function will run and will finish then application will countinue to run next to-do-list. but I could not do it. There is webview and i run webview in runuithread But i am not sure that what i do. 2- I run javascript command inside webview. sometimes javascript or webview gives error then I got this error "application has stopped" . I want to avoid from it. If you can do with in 1-2 hours . We can work and finish it otherwise please dont offer. I dont have time to wait.