IE event.srcElement和FF event.target 功能比较

<div id="div_001">
<form id="form_001">
<input type="button" id="button_001_id" name="button_001_Name" value="单击查看" class="button_001_Class" onclick="Get_srcElement(event)">
<select name="selectname" onchange="alert(event.srcElement.options[event.srcElement.selectedIndex].value);">
<option value=001>1</option>
<option value=002>2</option>
<option value=003>3</option>
<option value=004>4</option>
<option value=005>5</option>
</select>
</form>
</div>
<script>
function Get_srcElement(evgl)
{
　　var srcElement=""
　　 //判断是IE 还是Firefox
　　var evg=evgl.srcElement?evgl.srcElement:evgl.target;
　　srcElement = srcElement + "\n" + "button_001_id----event.srcElement.id : " + evg.id
　　srcElement = srcElement + "\n" + "input---event.srcElement.tagName : " + evg.tagName
　　srcElement = srcElement + "\n" + "button---event.srcElement.type : " + evg.type
　　srcElement = srcElement + "\n" + "单击查看---event.srcElement.value : " + evg.value
　　srcElement = srcElement + "\n" + "button_001_Name---event.srcElement.name : " + evg.name
　　srcElement = srcElement + "\n" + "button_001_Class---event.srcElement.className : " + evg.className
　　//IE 支持parentElement FireFox支持parentNode
　　srcElement = srcElement + "\n" + "form_001---event.srcElement.parentElement.id : " + 　　　　evg.parentNode.id
　　srcElement = srcElement + "\n" + "event.srcElement.getattribute : " + evg.getAttribute
　　alert(srcElement);
}
</script>