Try this.
sync on
sync rate 50
I removed the # as you only need those if you have decimal places like 2.304 the screen will never be like that
height=screen height()/2
width=screen width()/2
set window position height, width
set window title "Tibia Ages II"
set display mode 800, 600, 0
set window on
`I just moved this above the image
set image colorkey 255, 0, 255
load image "sprites/316.bmp", 1
do
`try this way
`sprite 1,height,width,1
`I commented it out so if you don't want to do it this way you don't have to
paste image 1, height, width
loop
wait key
I haven't tested it but it should work.
Hope I helped!
I keep runing nowhere fast!