Washer will not start, only spins

I ahve a MAYTAG model LAT8416AAE. it was woking fine until three hours ago. it stopped. if you turn the knob to SPIN, thenit will spin. it will not on any other setting. please advise
thanks

If it fills with water in the wash moder, will it agitate?

It will not even fill up with water. you can not even heat it clicking. it will spin only when you turn the knob to SPIN. it will not do anything if you turn the knob to anything else.
the machine is Maytag LAT8416-AAE.
thanks

I would pull the clear plastic hose that goes to the bottom of the tub and blow in it. The water level switch should click open. If it does, put the hose back on the tub and pull it off the water level switch. Blow in it to clear it out, then see if it now works. If it does, pump some vinegar down the plastic hose with a turkey baster to dissolve laundry detergent residue in the bottom of the tub.