Hi guys,

I'm new in Javascript, and have the following code:

HTML Code:
<script type="text/javascript">
		function changeFunc() {
			var selectBox = document.getElementById("selectBox");
			var selectedValue = selectBox.options[selectBox.selectedIndex].value;
			if (selectedValue == "Configuration1")
				document.getElementById("demo").innerHTML = "Hello World";
			if (selectedValue == "Configuration2")
				document.getElementById("demo2").innerHTML = "demo 2";
		}
	</script>

	<p align="center">
		<select id="selectBox" name="ConfigurationList" onclick="changeFunc();">
			<option value="Configuration1">CPU - 1GHz / RAM 1GB / HDD 50GB</option>
			<option value="Configuration2">CPU - 1.44GHz / RAM 1GB / HDD 50GB</option>
		</select>
	</p>
	
	<p id="demo"></p>
	<p id="demo2"></p>
When submit code, I choose Configuration1, it show Hello World, then I choose Configuration2, it show both Hello World and demo 2.
So, how can I do to show only one everytime after clicked?
Thanks in advance.
nganndt