In every negotiation, there comes a time when the other side rejects your idea, no matter how well you have done your homework or how reasonable you think your proposal is -- especially when negotiating for more money. You can't force someone to agree with you. So what can you do to turn a "no" into a "yes"?

Don't Take No for an Answer

Assume that "no" merely means "not yet," especially early on in the negotiation. This is a concept that every child, and every good salesperson, knows. You will be a better negotiator the minute you act on it

Understand the Other Side

People say "no" when their interests are not being met. Your manager's interests may include keeping a valuable employee, not setting a bad precedent for future negotiations, or staying within her budget. Your first task in this negotiation is to understand her interests.
How? Ask about them. You could say, "I think we could make more progress here if we talked about our goals for this negotiation. Here is what I am trying to achieve... What are your goals?" Or you could say, "If I were in your position, I would be especially concerned about staying within my budget and retaining a skilled employee. Are there other key matters I would be overlooking?" Ultimately, you need to consider the interests of both sides to come up with options that satisfy them.

Solve the Problem Together

Once you understand your manager's interests, work together to address them. Persuade her to join you in crafting a solution. You might say, "I think we have a joint problem here. If we are going to reach an agreement, we will have to find an option that meets both of our interests. I think we can do that most efficiently by working together to come up with good solutions."
If your manager seems amenable, provide guidelines for your joint problem-solving effort. For example, you could say, "I think if we put our heads together and brainstorm for the next 20 minutes, we could generate a lot of ideas. Then we can take 15 minutes to select the most promising ones and refine them for consideration. Can we agree to brainstorm -- without commitment -- for that time period?" With hard work, and a little luck, this activity should carry you past the resistance and lead to an agreement.

Consider Your Alternatives

If you have tried to understand the other side's interests and develop options that satisfy them, but you are still getting a "no," you have a choice to make. You can agree to whatever option your manager does accept, or you can pursue alternatives. An alternative might be making an appointment to talk with someone higher up in the organization who may have the authority to make a better deal. Or you might begin to actively look for other positions in the company or elsewhere. Or you might decide to wait and try again later. In any case, make sure you leave the door open as you walk through it. You could say, "I appreciate the time we have spent trying to reach an agreement. Right now I don't feel we are close enough to continue this conversation. Perhaps we could revisit this topic in a few days and see where we stand?"
The key to negotiating is to avoid letting a negative response become an obstacle to agreement. You can do that by recognizing the legitimate reasons causing someone to resist your idea, and then working together to address them. Not only will this approach make agreement more likely, but it also will cause the other person to appreciate the respect you have demonstrated -- a good outcome for any negotiation.