instances and variables

[sqidwarf]

ok in the game im making there are more then one of the same instances in each fight. (sometimes there might be 5 warriors) I cant figure out how to find the instance of an object with the most of a variable such as movement
or maybe you could suggest another way to do this

[IsmAvatar]

//fastest(obj)
//by IsmAvatar
//obj is an object or the keyword all
//returns the instance id of obj with the highest speed

var big, ID;
big = 0; ID = noone
for (m = 0; m < instance_number(argument0); m += 1) {
 zz = instance_find(argument0,m)
 if zz.speed > big {
  big = zz.speed
  ID = zz
 }
}
return ID