var ArrayList = Class.create();

ArrayList.prototype = 
{
  initialize: function()
  {
    this.aList = [];
  },
  
  Count: function()
  {
    return this.aList.length;
  },
  
  Add: function(object)
  {
    return this.aList.push(object);
  },
  
  GetAt: function(index)
  {
    if(index > -1 && index < this.aList.length)
      return this.aList[index];
    else
      return undefined;
  },
  
  Clear: function()
  {
    this.aList = [];
  },
  
  RemoveAt: function(index)
  {
    var m_count = this.aList.length;
            
    if ( m_count > 0 && index > -1 && index < this.aList.length ) 
    {
      switch( index )
      {
        case 0:
          this.aList.shift();
          break;
        case m_count - 1:
          this.aList.pop();
          break;
        default:
          var head   = this.aList.slice( 0, index );
          var tail   = this.aList.slice( index + 1 );
          this.aList = head.concat( tail );
          break;
      }
    }
  },
  
  Insert: function(object, index)
  {
    var m_count = this.aList.length;
    var m_returnValue = -1;

    if ( index > -1 && index <= m_count ) 
    {
      switch(index)
      {
        case 0:
          this.aList.unshift(object);
          m_returnValue = 0;
          break;
        case m_count:
          this.aList.push(object);
          m_returnValue = m_count;
          break;
        default:
          var head      = this.aList.slice(0, index - 1);
          var tail      = this.aList.slice(index);
          this.aList    = this.aList.concat(tail.unshift(object));
          m_returnValue = index;
          break;
      }
    }
            
    return m_returnValue;
  },
  
  IndexOf: function(object, startIndex)
  {
    var m_count       = this.aList.length;
    var m_returnValue = - 1;
            
    if ( startIndex > -1 && startIndex < m_count ) 
    {
      var i = startIndex;

      while( i < m_count )
      {
         if ( this.aList[i] == object )
         {
            m_returnValue = i;
            break;
         }
                    
         i++;
      }
    }
            
    return m_returnValue;
  },
  
  LastIndexOf: function(object,startIndex)
  {
  var m_count       = this.aList.length;
   var m_returnValue = - 1;
            
   if ( startIndex > -1 && startIndex < m_count ) 
   {
      var i = m_count - 1;
                
      while( i >= startIndex )
      {
         if ( this.aList[i] == object )
         {
            m_returnValue = i;
            break;
         }
                    
         i--;
      }
   }
            
   return m_returnValue;
  }
}