[nubideus]

" asd ".slice(1, -1)

while

var str:String = " asd  asasd  ";
var spaceCode:uint = " ".charCodeAt(0);
 
var left:uint = 0;
var right:uint = str.length;
var result:String = str;
 
while(left < right){
  if(str.charCodeAt(left) !== spaceCode) break;
  left++;
}
while(left < right){
  if(str.charCodeAt(right - 1) !== spaceCode) break;
  right--;
}
if(right - left ^ str.length){
  result = str.substring(right, left);
}else if(left === right) result = "";