All statistic analysis of this research are based on the Intent-to-treat method, which follow up participants who cannot finish the whole study process (i.e. drop out from the study). The investigators still ask them to do the outcome measurement. All the data will be count into the original groups to do further analysis in order to get a conservative conclusion. Researchers will key-in the data the investigators will use SPSS 16.0 to do the statistical analysis. The significant level will be set at 0.05. Main variables and methods for analysis are listed below: