jus wanted to say dat im not very learned in dis field to help answer The Thespains questions..& i wud like to apologise to him 4dat ..bu the replies given by brother Desai & brother Akulion are both very well xplained & clear (mashaallah) ..Their comments have also helped me to understand a few things too. ..jazahkallah & may Allah SWT reward accordingly & bless u wiv more knowledge to share.Ameen.