This code works if I change the if/else statements to simply if statements. Why does it not work with the if/else statements? It keeps evaluating the 3rd condition as true all the time and writes in "IBM: $1250"

Code JavaScript:
<script language="javascript" type="text/javascript">
 
var compCosts = new Array();
compCosts[1] = 1000;
compCosts[2] = 500;
compCosts[3] = 1250;
 
 
function up_dater()
{
 
    var orderDetails = "";    
 
    formElement = document.form1.processor;
    if (formElement[0].checked == true)
    {
        orderDetails = "Intel : $" + compCosts[formElement[0].value];
    }    
    else if (formElement[1].checked == true)
    {
        orderDetails = "AMD : $" + compCosts[formElement[1].value];
    }
    else (formElement[2].checked == true)
    {
        orderDetails = "IBM : $" + compCosts[formElement[2].value];
    }
 
    document.form1.txtorder.value = orderDetails;    
 
 
}
 
</script>
</head>
<body>
 
<form name=form1>
Choose a Processor<br />
       <input type="radio" name=processor value="1" />Intel<br />
       <input type="radio" name=processor value="2" />AMD<br />
       <input type="radio" checked name=processor value="3" />IBM<br /><br />
 
        <input type="button" name="updater" value="Update Price" onclick="up_dater()" /><br />
        <textarea name="txtorder" cols="30" rows="20" id="txtorder"></textarea>
 
 
</form>