function xspec,win,spix,lbkg=lbkg,rbkg=rbkg,xaxis=xaxis,lambda=lambda,sanoff=sanoff

    LAMP function to extract the specular intensity from a workspace.
    It simply integrates the counts within a certain range of x-pixels and subtracts the backgrounds (if specified)
    It also (correctly) calculates the errors and weights by the number of pixels in each range

    NECESSARY VARIABLES:
    win = the input workspace.  This has usually been passed through mload, but will also work for TOF data loaded directly
    spix = two element array with the left and right pixels that limit the width of the specular ridge

    OPTIONAL VARIABLES:
    lbkg = two element array with the left and right pixels that limit the background to the LEFT of the specular ridge
    rbkg = a two element array with the left and right pixles that limit the background to the RIGHT of the specular ridge
    In reality, the two optional variables are interchangeable
        - i.e. left and right don't matter.  What matters is that two separate pixel ranges can be used for background
    xaxis = a choice of the final x-axis values
        You may choose the x-axis in Qz (xaxis = 'q')    (default choice)
                      or theta_in (xaxis='san')
    lambda = the wavelength.  If unspecified, the wavelength will be taken from the data parameters

    sanoff = an offset in the sample angle in degrees.  
        This will be ADDED to the recorded sample angle

    OUTPUT VARIABLES
    wout is the workspace containing the specular intensity, background subtracted, with the x-axis = the y axis for win

    e.g. type at LAMP interface:
        w2=xspec(w1,[60,85],lbkg=[11,59],rbkg=[120,140])