5. BASIC AND DILUTED LOSS PER SHARE (Tables)
12 Months Ended
Dec. 31, 2019
Earnings Per Share [Abstract]  
Schedule of potential common stock equivalents not included in the calculation of diluted net loss per common share

The following potential common stock equivalents were not included in the calculation of diluted net loss per common share because the inclusion thereof would be anti-dilutive (in thousands):

 

   Year Ended December 31, 
   2019   2018 
Stock Options   2,934    2,477 
Unvested restricted stock   486    258 
Warrants   765    765 
    4,185    3,500