I just started at a high-intensity company doing graphic and web work. My boss had worked with me before at a third party company and loved my work, and offered for me to come on board full time with him.
Right now I'm working part time while my 2 weeks notice from my current job. I had to do some changes to the website, but I both misunderstood what he exactly wanted and some links I had created were messed up, and my boss is saying that's why we didn't have any sales yesterday (even though it was easter).
How can I best come back from a big screw up right off the bat?