#build a dynamic sql statement
my $Sql_str = &BuildSQLString($cMssFactBag);
print $Sql_str;
#I print here I get no SQL statement

##</code><code>##

sub BuildSQLString
{
...
$dynam_Sql_stmt = join(" ",$dynam_Sql_stmt, "from $p_str_tblName where RECORDXFEREDTOFILE = 'I'");

#I print here I a SQL statement

return $dynam_Sql_stmt;

}