Keystroke Commands 

?	Print help
p	Print photometry for star nearest the cursor
l	List the current psf stars
a	Add star nearest cursor to psf star list
f	Fit the psf
r	Review the fit for all the psf stars
s	Subtract fitted psf from psf star nearest cursor
d	Delete psf star nearest cursor from psf star list
w	Write the psf to the psf image
z	Rebuild the psf from scratch
q	Quit task

	Colon Commands

:p [n]	Print photometry for star n
:a [n]	Add star n to psf star list
:d [n]	Delete star n from psf star list
:s [n]  Subtract fitted psf from psf star n   

	Colon Parameter Editing Commands

# Data dependent parameters which affect the psf computation 

:scale	   [value]	Show/set the image scale (units / pixel)
:fwhmpsf   [value]	Show/set the fwhm of psf (scale units)
:datamin   [value]	Show/set the minimum good data value (counts)
:datamax   [value]	Show/set the maximum good data value (counts)
:matchrad  [value]	Show/set matching radius (scale units)

# Psf computation parameters

:psfimage   [name,name]	Show/set the psf image and groupfile
:function   [string]	Show/set the analytic psf function
:varorder   [integer]	Show/set order of psf function variability
:nclean	    [integer]	Show/set number of cleaning iterations
:saturated  [y/n]	Show/set the use saturated star flag
:psfrad	    [value]	Show/set the psf radius (scale units)
:fitrad	    [value]	Show/set the fitting radius (scale units)