how to find the tab id or page name of the privious page

                            I want to know the tab id or page name of the privious page.

                            I am having two tab in the solpart menu one is Commercial insurance and other one is Personal insurance  and also having other tab Products that will  not disply in the solpart menu tab, by clicking  Commercial  or personal insurance I will redirect the control to Product page ,in Product page i want to know which tab or page name was clicked(ie: commercial tab or insurance tab)