use this code
REM Project: MyFirstFPS
REM Created: 12/05/2007 17:31:59
REM
REM ***** Main Source File *****
REM
REM Set Client Options
SYNC ON
SYNC RATE 0
HIDE MOUSE
REM Make Floor
MAKE OBJECT PlAIN 6,1000,1000
XROTATE OBJECT 6,-90
COLOR OBJECT 6,RGB(50,55,55)
REM Make Main Character
MAKE OBJECT SPHERE 1,50
COLOR OBJECT 1,RGB(0,255,0)
POSITION OBJECT 1,0,2,0
HIDE OBJECT 1
REM Make Enemy Character
MAKE OBJECT SPHERE 2,50
COLOR OBJECT 2,rgb(255,0,0)
POSITION OBJECT 2,130,0,0
REM Make WallS
MAKE OBJECT BOX 3,1000,100,5
POSITION OBJECT 3,0,0,250
MAKE OBJECT BOX 7,1000,100,5
POSITION OBJECT 7,0,0,-250
MAKE OBJECT BOX 8,5,100,1000
POSITION OBJECT 8,250,0,0
MAKE OBJECT BOX 9,5,100,1000
POSITION OBJECT 9,-250,0,0
REM Make Ammo CLip
MAKE OBJECT BOX 4,20,50,20
COLOR OBJECT 4,RGB(255,0,255)
POSITION OBJECT 4,-40,0,0
REM Make Ammo Crate
MAKE OBJECT BOX 5,20,30,70
COLOR OBJECT 5,RGB(255,0,200)
POSITION OBJECT 5,150,0,-200
REM Set Up Shooting Limb
MAKE OBJECT TRIANGLE 9999,0,0,0,0,0,0,0,0,0
MAKE MESH FROM OBJECT 1,9999
DELETE OBJECT 9999
ADD LIMB 1,1,1
OFFSET LIMB 1,1,0,0,500
HIDE LIMB 1,1
REM nEW LIMB
ADD LIMB 1,2,1
OFFSET LIMB 1,2,0,0,OBJECT SIZE Z(1)/2
HIDE LIMB 1,2
ADD LIMB 1,3,1
OFFSET LIMB 1,3,0,0,-OBJECT SIZE Z(1)/2
HIDE LIMB 1,3
ADD LIMB 1,4,1
OFFSET LIMB 1,4,0,0,OBJECT SIZE X(1)/2
HIDE LIMB 1,4
ADD LIMB 1,5,1
OFFSET LIMB 1,5,0,0,-OBJECT SIZE X(1)/2
HIDE LIMB 1,5
DELETE MESH 1
REM Move objects up
FOR OBJECT =1 TO 5
POSITION OBJECT object,Object position x(OBJECT),OBJECT SIZE Y(OBJECT)/2,OBJECT POSITION Z(OBJECT)
NEXT OBJECT
FOR OBJECT =7 TO 9
POSITION OBJECT object,Object position x(OBJECT),OBJECT SIZE Y(OBJECT)/2,OBJECT POSITION Z(OBJECT)
NEXT OBJECT
REM Define Some Variables
EnemyHP=5000
Ammo=1000
MaxAmmo=1000
Clips=3
MaxClips=10
reload=0
time#=0
REM Start Main Loop
Do
REM Set Up Player Location
X#=OBJECT POSITION X(1)
Y#=OBJECT POSITION Y(1)
Z#=OBJECT POSITION Z(1)
REM Display HUD
REM Display FPS
` TEXT 0,0, "FPS: " + STR$(SCREEN FPS())
REM Display Ammo
` TEXT 0,SCREEN HEIGHT()-50, "Ammo: " + STR$(ammo) + "/" + STR$(Clips)
REM Enemy HP
IF OBJECT EXIST(2)=1
CENTER TEXT OBJECT SCREEN X(2),OBJECT SCREEN Y(2)-70, "Enemy HP: " + STR$(enemyhp)
ENDIF
REM crosshair
CIRCLE SCREEN WIDTH()/2,SCREEN HEIGHT()/2,20
REM Clip Label
IF Object Exist(4) Then CENTER TEXT OBJECT SCREEN X(4),OBJECT SCREEN Y(4)-70,"Ammo Clip"
REM Crate Label
IF Object Exist(5) Then CENTER TEXT OBJECT SCREEN X(5),OBJECT SCREEN Y(5)-70,"Ammo Crate"
REM Set Up Character Controls
REM Movement
IF KEYSTATE(17)=1 THEN MOVE OBJECT 1,0.5
IF KEYSTATE(31)=1 THEN MOVE OBJECT 1,-0.5
IF KEYSTATE(30)=1 THEN MOVE OBJECT LEFT 1,0.3
IF KEYSTATE(32)=1 THEN MOVE OBJECT RIGHT 1,0.3
REM Jumping
IF SPACEKEY()=1 and JUMPING#=0 THEN JUMP#=1
REM Jump Condition
IF JUMP#=1
GROUND#=Y#
JUMP_SPEED#=1
JUMPING#=1
JUMP#=0
ENDIF
REM Jump Calculation
IF JUMPING#=1
DEC JUMP_SPEED#,0.01
y#=y#+JUMP_SPEED#
POSITION OBJECT 1,X#,Y#+JUMP_SPEED#,Z#
IF Y#<=GROUND#
JUMPING#=0
Y#=ground#
endif
ENDIF
REM Set Up Camera Controls
CAMY#=CAMY#+MOUSEMOVEX()*0.1
CAMX#=CAMX#+MOUSEMOVEY()*0.1
IF CAMX#>90 AND CAMX#<135 THEN CAMX#=90
IF CAMX#>270 AND CAMX#<225 THEN CAMX#=90
ROTATE CAMERA CAMX#,CAMY#,0
`XROTATE CAMERA CAMX#
ROTATE OBJECT 1,CAMX#,CAMY#,0
`XROTATE OBJECT 1,CAMX#
REM Camera
POSITION CAMERA X#,Y#,Z#
REM Reload
IF KEYSTATE(19)=1 and MOUSECLICK()=0 AND Clips>0 AND AMMO<MaxAmmo THEN reload=1
IF reload=1 THEN INC time#,0.001
IF Time#>1 Then Ammo=MaxAmmo:DEC Clips,1:Time#=0:reload=0
IF Reload=1 THEN CENTER TEXT SCREEN WIDTH()/2,SCREEN HEIGHT()/2,"Reloading..."
REM Pickup ammo CLIP
IF Object Exist(4)
IF Clips<MaxClips AND INTERSECT OBJECT (4, X#,Y#-50,Z#,X#,Y#,Z#)>0
IF Clips<MaxClips
INC Clips,1
Delete Object 4
ENDIF
ENDIF
ENDIF
REM Pickup Ammo crate
IF Object Exist(5)
IF Clips<MaxClips AND INTERSECT OBJECT (5,Z#,Y#-50,Z#,X#,Y#,Z#)>0
IF Clips<MaxClips
Clips=MaxClips
Ammo=MaxAmmo
Delete Object 5
ENDIF
ENDIF
ENDIF
REM Shooting
IF MOUSECLICK()=1 AND KEYSTATE(19)=0
REM Decrease Ammo
IF Ammo>0
DEC Ammo,1
Wait 100
ENDIF
REM Check Object Exists
IF OBJECT EXIST(2)=1
REM Check the player has ammo
IF Ammo>0
REM Check if player is aiming at enemy
IF INTERSECT OBJECT(2,LIMB POSITION X(1,1),LIMB POSITION Y(1,1),LIMB POSITION Z(1,1),X#,Y#,Z#)>0
REM Decrease Enemy Health
DEC EnemyHP,1
ENDIF
ENDIF
ENDIF
ENDIF
REM Kill enemy if HP is zero
IF enemyhp=0
IF OBJECT EXIST(2)=1
DELETE OBJECT 2
ENDIF
ENDIF
REM Floor Collision
while INTERSECT OBJECT (6,X#,(Y#-26),Z#,X#,Y#,Z#)>0
inc y#
POSITION OBJECT 1,X#,Y#,Z#
JUMPING=0
endwhile
REM WALL COLLISIONS
IF INTERSECT OBJECT (3,LIMB POSITION X(1,2),LIMB POSITION Y(1,2),LIMB POSITION Z(1,2),X#,Y#,Z#)
MOVE OBJECT 1,-1
ENDIF
IF INTERSECT OBJECT (3,LIMB POSITION X(1,3),LIMB POSITION Y(1,3),LIMB POSITION Z(1,3),X#,Y#,Z#)
MOVE OBJECT 1,1
ENDIF
IF INTERSECT OBJECT (3,LIMB POSITION X(1,4),LIMB POSITION Y(1,4),LIMB POSITION Z(1,4),X#,Y#,Z#)
MOVE OBJECT LEFT 1,1
ENDIF
IF INTERSECT OBJECT (3,LIMB POSITION X(1,5),LIMB POSITION Y(1,5),LIMB POSITION Z(1,5),X#,Y#,Z#)
MOVE OBJECT RIGHT 1,1
ENDIF
FOR OBJECT =7 TO 9
IF INTERSECT OBJECT (OBJECT,LIMB POSITION X(1,2),LIMB POSITION Y(1,2),LIMB POSITION Z(1,2),X#,Y#,Z#)
MOVE OBJECT 1,-1
ENDIF
IF INTERSECT OBJECT (3,LIMB POSITION X(1,3),LIMB POSITION Y(1,3),LIMB POSITION Z(1,3),X#,Y#,Z#)
MOVE OBJECT 1,1
ENDIF
IF INTERSECT OBJECT (3,LIMB POSITION X(1,4),LIMB POSITION Y(1,4),LIMB POSITION Z(1,4),X#,Y#,Z#)
MOVE OBJECT LEFT 1,1
ENDIF
IF INTERSECT OBJECT (3,LIMB POSITION X(1,5),LIMB POSITION Y(1,5),LIMB POSITION Z(1,5),X#,Y#,Z#)
MOVE OBJECT RIGHT 1,1
ENDIF
NEXT OBJECT
SYNC
LOOP
The main problem was a typo, where it says jumping#=0, someone forgot the #. Ive also changed a couple other lines, so have a look
