//
// Evaluate expression.
// If the expression involves only ONE external symbol, the expression is
-// UNDEFINED, but it's value includes everything but the symbol value, and
+// UNDEFINED, but its value includes everything but the symbol value, and
// 'a_esym' is set to the external symbol.
//
int evexpr(TOKEN * _tk, uint64_t * a_value, WORD * a_attr, SYM ** a_esym)