null cancelling movement

this allows you to continue moving instead of completely stopping when holding 2 different movement keys that are in different directions (A and D, W and S)

put this in your autoexec or main cfg file, either one works
Code:
bind w +mfwd
bind s +mback
bind a +mleft
bind d +mright

alias +mfwd "-back;+forward;alias checkfwd +forward"
alias +mback "-forward;+back;alias checkback +back"
alias +mleft "-moveright;+moveleft;alias checkleft +moveleft"
alias +mright "-moveleft;+moveright;alias checkright +moveright"
alias -mfwd "-forward;checkback;alias checkfwd none"
alias -mback "-back;checkfwd;alias checkback none"
alias -mleft "-moveleft;checkright;alias checkleft none"
alias -mright "-moveright;checkleft;alias checkright none"
alias checkfwd none
alias checkback none
alias checkleft none
alias checkright none
alias none ""
(stolen from this tf2 thread)