this is supposed to convert expressions using a stack
like "6 + 2.1 * 4.2"
becomes something like
" 6 2.1 4.2 *+"

protected String toPostFix ()
{
StackB x = new StackB ();
String op = "+-*/%^";
String post = "";
StringTokenizer t = new StringTokenizer (s, " ");
String theToken = "";
while (t.hasMoreTokens ())
{
System.out.println ("im into#1 there!");
theToken = t.nextToken ();
System.out.println ("the token is:" + theToken);
if (op.indexOf (theToken) >= 0)
{
while (!x.empty () && higher (x.peek (), theToken))
{
System.out.println ("im into #2here!");
x.push (theToken);
theToken=x.pop();
// post += x.pop ();
System.out.println (x.top);
post += theToken;

}

}

else
{
post += theToken;
//to postfix ... "3 + 5.2 * -8.72"
}
System.out.println (post);
while (!(x.empty ()))
{
theToken = x.pop ();
post += theToken;
System.out.println ("im in!");
// post += " " + theToken + " ";

}
}


return post;
}