Animation stopping while on "wait()"...?

Hello there!, This is another problem I found while doing a Script, Once the animation plays on the character and pressses any moving key the Animation stops.

-- The preset before the animation plays is hum.Walkspeed = 0 and same with jump power. 
Anim:Play()
wait(1.8) --If you press W, A, S or D in this interval the animation will automatically stop, even with Walkspeed and jumppower set to 0.
Anim:stop()
--below here the script continues

I tried to figure out why does this happens, I have no clue... Help? There is No errors/Warnings ...