gears not working

[Comfort1]

I used my mower and attempted to mow down heavy weeds and after parking it and trying to use it again the gears were not working. It won't move forward or reverse. Can somebody tell me what to look for. I have a Craftsman 917-249893 model which is pretty old but other than this runs great.

Thanks

 

[mechanic mark]

Recheck number under seat, not coming up. Check drive belt for replacement.