Edit in JSFiddle

function argTest(){
	var i = 0;
	for(i;i<arguments.length;i++){
  	alert(arguments[i]);
  }
}

<input type="button" value="가" onclick=argTest("가")>
<br/>
<input type="button" value="가,나" onclick=argTest("가","나")>
<br/>
<input type="button" value="가,나,다" onclick=argTest("가","나","다")>
<br/>
<input type="button" value="가,나,다,라라라" onclick=argTest("가","나","다","라라라")>

input {
  width:110px;
}