(Portland, OR)  --  A woman accused of assaulting and robbing an 89-year-old Southeast Portland woman will stand trial after pleading not guilty.  Thirty-three-year-old Tiffany Denise Smith entered the plea yesterday during her arraignment.  She's accused of knocking the victim to the ground and stealing her purse in front of the victim's home on Southeast 148th Place.  Police allege that Smith had stalked the victim prior to the assault and robbery on January 7th.