small website update in php, mysql .

this is a very small and easy work. need to update small things in a webpage made with php and mysql. you need to resize the size of images that are shown, and instead of showing 3 images in 1 row, we need to show 4 images in each row. also if the user clicks on any image, a pop up screen comes up. this screen is currently not being centered properly near the image clicked. this needs to be fixed. this is very small and easy work and probably you can do it in 1-2 hours. bid only if you can finish this task in 1 day. we would not give you the website access but we would send you the files so that you can make the changes required and send the file back to us