How to change company by the X++ code in AX 2009

sometimes you need to change company by code to get some information from company to put it in another one like update the price for company X by the price you get from company Y and this example will explain : 

void clicked()
{
inventtable _inventtable;
InventTableModule invtm;
InventTableModule invtmhaq;
int counter=0;
///////////////////////////////////////////////////////////////////////////////
////////////////////////////Code Begining//////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
ttsbegin;
        try
        {
              changecompany('sdx')
              {
                while select invtm
                {
                    if(invtm)
                    {
                        changecompany('haq')
                        {
                            while select forupdate invtmhaq where invtmhaq.ItemId == invtm.ItemId
                            {
                                if(invtmhaq)
                                {
                                      invtmhaq.Price= invtm.Price;
                                      invtmhaq.update();
                                      counter++;
                                 }
                            }
                        }
                    }
                }
              }
       }
            catch
                {
                Error(strfmt("Can not apple to insert "));
                }
 ttscommit;
 info(strfmt("Number Of rows Inserted : %1",counter));

}