var Toggle =1;
function DWtop(chk) {  
  Toggle = 0;  
  switch(chk) {
        case 1:
          pf.stop();
          break;
        case 2:
          pf.stop();
          break;
  }    
}

function DWstart(chk)  {  
  Toggle = 1;  
  switch(chk) {
        case 1:
          pf.start();
          break;
        case 2:
          pf.start();
          break;
  }    
}