there are two ways of solving ur 1st problm.
1-> u can use ajax to submit the img temp_name and then upload it when choose "browse" btn and can show a preview from the folder where the original img is uploaded.
bt it is a bit difficult.
2-> u can write a iframe(display none) which is the target of a form containing the img file.
then u can write a fnc onchange() of input type file where u can get the name of the file and submit the form and in another php file u can get the post value ie name of the img and upload it to a folder and use it...