if (screen.width < 1025) {
  document.write('<'+'link rel="stylesheet" href="css/res1000.css" />');
  }

  else if (1025 < screen.width < 1281) {
       document.write('<'+'link rel="stylesheet" href="css/res1200.css" />');
       }

        else if (1281 < screen.width < 1500) {
    		 document.write('<'+'link rel="stylesheet" href="css/res1400.css" />');
    		 }
    	
    		 else if (1500 < screen.width < 2000) {
             	  document.write('<'+'link rel="stylesheet" href="css/res1600.css" />');
        		  }