bottom of screen not working properly after replacment

after screen replacementthe slider works fine but the apps at the bottom of the screen,below the magnifying glass and dots, function like a home button.I am unable to move or open app, when an incoming call apperars i am unable to answer or ignore since it appears on the bottom? I have replaced a cracked screen and rechecked the 3 connections but am still having the problem. the screen function was fine before replacement of the screen. suggestions please...