I believe the &000 is being treated like a string and being ignored, so you are probably getting only 5000 + the number the user enters. Try changing the Sleep command to this and see if it helps:
Sleep(5000+($delaySeconds*1000))
The line above takes the number entered by the user and multiplies it by 1000 to give you the number of milliseconds, then adds it to the existing 5000.