...here you go:
;Artificial Intelligence Script:::::::::::::::::::::::::::::::::::::::::::::::::
desc = ENTER KEY Weapon Pick Up
;When player gets within 40 units of weapon pickup, custom HUD TEXT will display.
;If player presses ENTER KEY, weapon will be picked up, and added to player's weapon inventory.
;Triggers
:state=0:hudreset,hudx=50,hudy=90,hudsize=18,hudtext=Press ENTER KEY to pick up this weapon,hudname=WEAPONPROMPT,hudhide=1,hudmake=display,state=10
:state=10,plrdistwithin=40:hudshow=WEAPONPROMPT,state=12
:state=12,plrdistfurther=40:hudunshow=WEAPONPROMPT,state=12,state=10
;Player Press ENTER KEY
:state=12,scancodekeypressed=28:hudunshow=WEAPONPROMPT,playertake,coloff,rundecal=-1,plrsound=audiobank\items\pickupweapon.wav,state=14
;End of Script::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
That should work nicely for you.