\title{Background Correction}
This function use the background data to eliminate unwanted effects in signal.
The background correction establish the new Cy3 signal as Cy3 - BgCy3 and 
the new Cy5 as Cy5 - BgCy5.
\item{mySpot}{Spot object for one microarray.}
Spot object with the background correction done. 
## background correction and save it in c.spot
c.spot <- bg.correct(Simon)