Browse to file and send

i’am building a website that has a page where people can download a schedule as a PDF file.
This is the only thing that changes every week on the site.
Now i want to make a page where the owner can login and then goes to a page where a browse button is displayed when he clicks the browse button he can select the newest version of the pdf from his harddisk. and then click send to upload it to the server where it refresh the last version.
Is this possible ? and how can i make this ?
Does somebody have a tutorial ? or even the script ?

The login part is no problem only the browse to file and send to server part.
Would be nice if this can be done with PHP