question about makeplot()

["physiker11" <webmaster@xxxxxxxxxxxxxx>]

it seems that this command doesn't need openfile() to be able to 
write to a file, but at the same time it doesn't seem like i can set 
the write type (ie. overwrite, append)

Every time i call this function it overwrites the previous 
information. Is there a simple way around this?

ie. the first data set is overwritten by the 2nd. 

clearcontour()
addcontour(0,27.5)
addcontour(0,-27.5)
makeplot(4,1000,"helmholtz_results.txt",0)
clearcontour()
addcontour(0,0)
addcontour(40,0)
makeplot(4,1000,"helmholtz_results.txt",0)


Cheers