奇怪的height


<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> 
<HTML> 
<HEAD> 
<TITLE> New Document </TITLE> 
<META NAME="Generator" CONTENT="EditPlus"> 
<META NAME="Author" CONTENT=""> 
<META NAME="Keywords" CONTENT=""> 
<META NAME="Description" CONTENT=""> 
<script type="text/jscript"> 
onload=function(){ 
alert(document.getElementById("testHeight").height); 
} 
</script> 
</HEAD> <BODY> 
<input type="button" id="testHeight" value="奇怪的height" onclick="alert(document.getElementById('testHeight').height);"/> 
<input type="button" id="testHeight" value="奇怪的height2" onclick="alert(this.height);"/> 
</BODY> 
</HTML>