[lollypap54]

When player choose a checkpoint, give integer to them. Like this :
new cp[MAX_PLAYERS]
...
if(cp[pid]==0){
showcheckpoint blablabla;
cp[pid]=1;}
else { sendclientmessage(bla, bla, "you arleady have checkpointbal"); }

Now do checkpoint delete command
CMD:checkpointdelete(blala){
if(cp[pid]==1){
notshowcheckpointhere
cp[pid]=0;}

Hope understand how do it.