More doc updates.

JetCore.txt

@@ -1,4 +1,4 @@
-\documentclass{refman}
+\documentclass{book}
 
 \title{JET Extension Tags}
 \author{Bradford Matthew Arant Sr.}
@@ -87,6 +87,23 @@ perform the operations that JET provides.
 
 Use the call tag to evoke an executable file from a jet script. 
 
+The atrributes are:
+
+pgm
+
+argn
+
+name
+
+input
+
+\begin{verbatim}
+<call pgm="ls" arg1="-al" name="listing" />
+\end{verbatim}
+
+will call the ls command with parameter -al and place the output into
+a variable named 'listing'. 
+
 \section{comment}
 
 Use the comment tag to create a section in the jet script that can be