var popUpLogin=0; 
        function popUpLoginMyTeacher(URLStr, left, top, width, height) 
        { 
         if(popUpLogin) 
            { 
             if(!popUpLogin.closed) popUpLogin.close(); 
            } 
            popUpLogin = open(URLStr, 'popUpLogin', 'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=yes,copyhistory=yes,width='+width+',height='+height+',left='+left+', top='+top+',screenX='+left+',screenY='+top+'');
            
         var secured = document.getElementById('chkssl');
         if (secured != null)
         {
             if (secured.checked)
                document.forms[1].action = document.forms[1].action.replace('http:','https:');
             else
                document.forms[1].action = document.forms[1].action.replace('https:','http:');
         }
           
         document.forms[1].submit(); 
  }
  
  function clickButton() 
 {     
  if (event.keyCode == 13) 
  {      
   popUpLoginMyTeacher('', 0, 0, 1024, 740);
   return false;
  }
 }