BALANCE SHEETS [Parenthetical] - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Convertible preferred stock, par value	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	6,000,000	6,000,000
Convertible preferred stock, shares issued	0	0
Convertible preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	450,000,000	300,000,000
Common stock, shares issued	172,887,221	172,683,342
Common stock, shares outstanding	172,887,221	172,683,342