Change upload_max_filesize value for uploading a file of 48,2Mo


On my website hosted by ProFreeHost and online, I created a members area where users can upload audio and video files. I use for it Ajax and a PHP script but it seems that the upload max filesize is limited by default.
For a test, the mp3 file I tried to upload had 48,2 Mo for size and the PHP script condition "if (!isset($_FILES["file1"]["tmp_name"]))" returned "true" so the file were messing.

I verified my php script and there's no error inside and it works perfectly with smaller files.

The problem with the 48.2 Mo filesize is because de size of this is bigger than the max filesize limite.

Could you tell me wich is the default limit of upload filesize on ProFreeHost (for a free hosting) ?

How can I request to a admin the changing of this limit to solve my problem please ? Is there a way for it ?

Sorry for my limited english, I'm french.