It's perfectly OK to ask the OP to inform us of what he has attempted so far to solve his problem, in a polite, constructive way.
So many people were asking "What have you tried?" without any useful elaboration about what information would be helpful, that it was becoming rude. As of March 2013 that comment has been outright blocked.
See the message about the block for more constructive alternatives, and consider more specific comments addressing what's lacking in the question:
Please show your code.
or even:
Please explain what you mean by "not working".
You should always be polite - remember the rule "be nice". We're trying to "make the Internet a better place" here.
If you need to add any (or all) of these comments that's the mark of a bad question. Leaving these comments is the first step on getting a good question that people can answer.
If there's no effort to improve the post then it's the mark of a question that can be closed.
