PHP, javascript, mySQL

We have an existing site that was written about 4 years ago. It is written in PHP, mySQL and Javascript. We have a new feature we want to add. There is about 2,000 lines of code to review. So we want to be upfront about this. At some point in time we will want to redo the entire site, but for now we have to work with the existing code. The current site has a custom control panel that we built with another developer. The form allows a user to enter a product rental invoice and we want to modify the form. For a senior PHP LAMP developer this should not be too difficult but we admit there is a lot of code to review to understand what is going on as there were some changes made over the years. We estimate this form change should take a day due to the reviewing of code. Also, there are other cosmetic changes we need to the front end. These changes are minor and should take no more than an additional day or less of work. No script changes just design changes. But like all code, changing one thing can cause bugs. If we hire you for the first part, we will want to hire you for the 2nd part and we will provide full specs as well as graphic elements. Please start your bid with "Qwerty" so we know you are not using a bot and you can follow simple instructions . Blank bids will be deleted. We hope to build a long term relationship with you.