2个页面同时开着 按了按钮 数字马上出现另一个页面

HTML  CODE

< input  type ="button"  value ="open new win"  onclick ="openWin()" >
< input  type ="button"  value ="1"  onclick ="setValue('txt1')" >
< input  type ="button"  value ="2"  onclick ="setValue('txt2')" >
< input  type ="text"  id ="txt1" >
< input  type ="text"  id ="txt2" >

JS 

function  openWin()
... {
   window.open(window.location.href,"","width=200,height=200");
}
function  setValue(obj)
... {
   window.opener.document.getElementById(obj).value=event.srcElement.value;
}