Allow only pdf, doc, docx format for file upload?

You can use

<input name="Upload Saved Replay" type="file" 
  accept="application/pdf,application/msword,
  application/vnd.openxmlformats-officedocument.wordprocessingml.document"/>

whearat

• application/pdf means .pdf
• application/msword means .doc
• application/vnd.openxmlformats-officedocument.wordprocessingml.document means .docx

instead.

[EDIT] Be warned, .dot might match too.