need help plz, band sizes estimation - (Sep/28/2010 )

Dear best friends,
Could you plz help me.
I need to estimate sizes of protein bands in the attached image (marker band sizes are shown).
I donn 've gel documentation analayser software in the lab.
I greatly appreciate your help.
Many thanks in advance.
Yours,
Hamada.

measure the distance traveled by the markers and either calculate Rf and plot vs mw or just plot distance vs mw (can use log mw).

compare samples bands distance to plot and determine mw.

have in mind that actual band size of polypeptide may have an error of +_- up to 10%