I work as a middle man between homeowners and contractors, essentially a project manager. The contract for work is between the homeowner and GC. In this particular case, the contract was for 15,750 for impact windows. I personally ordered the windows which have a cost of roughly 9,000. The homeowner was informed on 8/15 that the windows were ready and we were just waiting on contractor to secure permit. On 8/26 the customer tried to cancel the commitment because she received a contract to sell her home. I explained that the realtor made a mistake if she did not disclose the existing contract for impact windows. The homeowner is not willing to honor the contract, and I have explained the windows are custom made and cannot be returned. I need to file a lien to recoup the cost of material (windows) and are unsure of my role in filing.