span를 이용한 html내 문자열 변경

<script>
function s_check()
{
  var aaa=document.getElementById("txtHint").innerHTML;
   alert(aaa);
   document.getElementById("txtHint").innerHTML="문자열변경";
}
</script>
</form><p>질문: <span id="txtHint" onclick="s_check()">기본문자열</span></p>
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기본문자열을 클릭하면
 
alert창에  기본 문자열이 나오고
문자열변경으로 내용이 변경 됨니다. 
 
 
<script>
function showHint(str)
{
 // if (str.length==0)
//  {
  var aaa=document.getElementById("txtHint").innerHTML;
   alert(aaa);
   document.getElementById("txtHint").innerHTML="zzzzzzzz";
//  return
//  }
/*
xmlHttp=GetXmlHttpObject()
if (xmlHttp==null)
{
alert ("Browser does not support HTTP Request")
return
}
var url="gethint.asp"
url=url+"?q="+str
url=url+"&sid="+Math.random()
xmlHttp.onreadystatechange=stateChanged
xmlHttp.open("GET",url,true)
xmlHttp.send(null)
*/
}
</script>
<form>
First Name:
<input type="text" id="txt1"
onkeyup="showHint(this.value)">
</form><p>Suggestions: <span id="txtHint">bbbbbbb</span></p>
======================================================
 
<SCRIPT>
function getID(oObject)
{
    var id = oObject.id;
 var va=id.value;
    alert("This object's ID attribute is set to \"" + id + "\"."+va);
 alert(document.getElementById['aaa']);
}
</SCRIPT>

<TABLE BORDER COLS=3><TR>
<TD ID="firstCell"  onclick="getID(this);">Table Cell 1</TD>
<TD ID="secondCell" onclick="getID(this);">Table Cell 2</TD>
<TD ID="thirdCell"  onclick="getID(this);">Table Cell 3</TD>
</TR></TABLE>
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