As you have not specified the full path the security data files, both data files must be in the current directory. The best method is to define the full path in the function:
Security("C:\the full path to my MetaStock Data\GC",C);
etc
wabbit
"The question of whether a computer can think is no more interesting than the question of whether a submarine can swim."
Edsgar W. Dijkstra
MS: 6.52 EOD, 7.x EOD, 8.0 PRO, 9.2 PRO w/QC, 10 PRO w/QC & MDK
For custom MetaStock programming : http://www.wabbit.com.au
My SkyPE status : 
My SkyPE account : wabbit.com.au