function MM_openBrWindow(url,windowName, width, height,top,left)
{ 
    
if(window.calInst==null)
{ 
 ;
} 
else 
{ 
    window.calInst.close(); 
    window.calInst=null; 
 
} 


window.calInst=window.open(url,windowName,"toolbars=no,location=no,directories=no,status=no,scrollbars=1,menubar=0,resizable=0,copyhistory=no, top="+ top +",left="+ left + ", width=" + width + ", height=" + height); 

return false; 

}