By Amy E. Feldman

PHILADELPHIA (CBS) - If you left a job but now want back in, or if you were laid off but hear of job openings at your old company, what should and what should you NOT do?

A Connecticut postal service worker was convicted of assault when he went to ask his former supervisor for his old job back but then pushed her and she fell and needed stitches. That can’t be how he pictured the reunion would work.

As the economy ramps back up and companies begin hiring after having layoffs in the past, many former employees think of reapplying at their old company. Unless you’ve signed a noncompete in the interim that would prevent you from going back, there is no reason why you can’t apply. But keep these thoughts in mind:

If you were not laid off but fired for cause or for poor performance, the company may not jump for joy when they get your resume so you may need a cover letter explaining how you’ve grown as an employee during your absence.

In any event, if you’ve maintained good relations with anyone at your old employer, reach out to that person and ask him or her to walk your resume into the hiring office rather than just mailing it to an HR rep you may not know. And if you don’t get a wildly enthusiastic response, never get pushy with the person to whom you’re speaking.