I can't get the value from unity to PHP

I can’t get the value from unity to PHP. It always prints “No information was collected” in unity no matter what I did. It worked perfectly when I used $sql = “INSERT INTO Acount(AcountID,Date) VALUES(‘$AccountID’,‘$Date’)”; in other php file. The PHP file is uploaded to a web host already. Scripts are posted in the comment.

You created a WWWForm but you never used it anywhere. You have to pass it to the WWW constructor:

// [ ... ]
WWWForm form = new WWWForm ();
form.AddField ("AccountIDpost",input);
WWW www = new WWW(checkAccountURL, form);
yield return www;
// [ ... ]