remove one node in xml???

Hi all,
This is 'manage_accounts.xml' file:
<?xml version = "1.0"?>
<MANAGE_ACCOUNTS>
<USER >
<USERNAME>a</USERNAME>
<PASSWORD>a</PASSWORD>
</USER>

<USER >
<USERNAME>b</USERNAME>
<PASSWORD>b</PASSWORD>
</USER >

<USER >
<USERNAME>c</USERNAME>
<PASSWORD>c</PASSWORD>
</USER >
</MANAGE_ACCOUNTS>

i want to remove node USER and it's content if i enter 'username' in textbox == 'username' in one node:
for ex:
enter "b" -> remove node USER which contain user b
result must be:

<?xml version = "1.0"?>
<MANAGE_ACCOUNTS>
<USER >
<USERNAME>a</USERNAME>
<PASSWORD>a</PASSWORD>
</USER>

<USER >
<USERNAME>c</USERNAME>
<PASSWORD>c</PASSWORD>
</USER >
</MANAGE_ACCOUNTS>

this is my script to do this:
<script language = "javascript">
<XML ID="customers" SRC = "manage_accounts.xml"></XML>
function delete_user()
{
var input = remove_form.txtUsername.value.toLowerCase();
var xmlDoc = new ActiveXObject("Microsoft.XMLDOM")
xmlDoc.async="false"
xmlDoc.load("manage_accounts.xml")

customers.recordset.moveFirst();
while (!customers.recordset.EOF)
{
var currentUserName = new String(customers.recordset("USERNAME"))
//change to lowercase
currentUserName = currentUserName.toLowerCase();

if(input == currentUserName)
{
var remove_node = xmlDoc.selectSingleNode("/MANAGE_ACCOUNTS/USER")
xmlDoc.documentElement.removeChild(remove_node)
}
customers.recordset.moveNext();
}//end of while (!customers.recordset.EOF)
}
</script>

but when i enter "a"or "b"or"c"-> it's alway delete the first node
result alway is:
<?xml version = "1.0"?>
<MANAGE_ACCOUNTS>
<USER >
<USERNAME>b</USERNAME>
<PASSWORD>b</PASSWORD>
</USER >

<USER >
<USERNAME>c</USERNAME>
<PASSWORD>c</PASSWORD>
</USER >
</MANAGE_ACCOUNTS>

i don't know how to solve this problem?

please help me, it's in urgent!
Thanks a lot..

Try something like:

YES, thank you very much mr. Bricker42!
it's work greate!

Thanks again..