I agree with some comments above.
Avoid putting salary expectations on the resumé, or even in the cover letter or even in the first interview. And try and get the employer to make a offer first, and negotiate upwards.
Yes, an employer will have a budget, and yes, the salary may be a decision factor which is exactly why you do not want to offer your salary expectations.
When asked about salary expectations, respond that you want to paid for your work depending on the expectations of the job. This means that you will be reasonable depending on expectations. It also tells the employer that you need to know more about the job before being ready to discuss salary expectations.
For example, your are seeking a job for IT technical support, then they add database administration. Or your are seeking a job as a programmer and then they tack on network administration. If you already have given your salary expectations, you will have a hard time moving upwards in your negotiations.
Above comments have indicated that the job will have a salary range -- you want to be offerred at the high end. But if you request the high end, the employer may remove you from the "short list" because another candidate seems to have a similar skill set. If you dodge answering the specifics for the salary request, you will probably stay on the "short list". Then on the second or third interview, the employer now realizes that you are the better choice than the candidate with lower salary expectations. And now you can go for the higher salary range.
If you give your salary expectations, you loose your negotiation posistion, and you may have to "low-ball" your expectations to ensure you make the short-list.
From an employer's perspective, I suspect they want to make sure the person they hire is happy. It costs then money and time to hire and train. Therefore, they will probably have a fair budget and expectations.